Potent antitumoral effects of a novel gene-viral therapeutic system CNHK300-mEndostatin in hepatocellular carcinoma

BACKGROUND

The expression of therapeutic gene and its anti-tumor effects will be augmented and a synergism of oncolytic virus with the therapeutic gene is speculated. This study was undertaken to assess the anti-tumor effects of a novel gene-viral therapeutic system CNHK300-mEndostatin (CNHK300-mE) in hepatocellular carcinoma (HCC).

METHODS

A novel gene-viral therapeutic system named CNHK300-mE was constructed using the human telomerase reverse transcriptase (hTERT) promoter to drive the expression of the adenovirus E1A gene and cloning the therapeutic gene mouse endostatin into the adenovirus genome. By the tissue culture infectious dose 50 (TCID50) method and cytoviability assay, the replicative and cytolytic capabilities of CNHK300-mE in two HCC lines (HepGII and Hep3B) and one normal cell line (MRC-5) were analyzed, and the transgene expressions of mouse endostatin in vitro and in vivo were detected by Western blotting and ELISA assay. Tumor growth suppression and anti-angiogenesis effects in vivo were investigated using nude mice xenografts model derived from SMMC-7721 HCC cells.

RESULTS

The 3296-fold replicating capacity of CNHK300-mE in HCC cell lines versus in the normal cell line at 96 hours post infection and the 25-fold effective dose for killing 50% cells (ED50) in the normal cell line versus HCC cell lines, which were both superior to ONYX-015, were observed. Tumor growth suppression of CNHK300-mE superior to either Ad-mE or ONYX-015 was demonstrated (P < 0.01) and the anti-angiogenic effects in vivo superior to Ad-mE were also observed with immunohistochemical staining of von Willebrand factor. In comparison with non-replicative adenovirus Ad-mE, the transgene expression of mE mediated by CNHK300-mE was significantly higher in vitro (P < 0.005) and in vivo (P < 0.05).

CONCLUSION

Being capable of replicating in and lysing the telomerase-positive HCC cells and mediating effective expression of the therapeutic gene in vitro and in vivo, the novel gene-viral therapeutic system CNHK300-mE is potentially effective in the treatment of HCC.

[CNHK200-hA-a gene-viral therapeutic system and its antitumor effect on lung cancer]

OBJECTIVE

To develop a novel vector system, which combines the advantages of the gene therapy, antiangiogenic therapy and virus therapy, and to observe its effect on lung cancer.

METHODS

Human angiostatin gene hA(k1-5) was inserted into the genome of the replicative virus specific for the tumor cells by virus recombination technology. The expression of hA(k1-5), its effect on tumor growth in vitro and in vivo were studied.

RESULTS

A new kind of gene-viral vector system, designated as CNHK200-hA(k1-5), in which the E1b55 000 gene was deleted but the E1a gene of adenovirus preserved, was constructed. The novel vector system possessed the same property as the replicative virus ONYX-015, which replicates in p53- tumor cells but not in normal cells, thus specifically kills tumor cells. In vitro, CNHK200-hA and Ad-hA both could kill A549 tumor cells but the latter needed 100 times more MOI to achieve the same amplitude of cell killing. In vivo, the therapeutic effect of CNHK200-hA on human lung cancer A549 xenograft in nude mice was significantly better than that of Ad-hA and that of tumor-replicative virus ONYX-015.

CONCLUSION

CNHK200-hA(k1-5), a novel vector is constructed in which the angiostatin gene is inserted into the genome of the replicative adenovirus cytotoxic to p53-negative tumor cells. It has the advantages of specific tumor targeting, high level gene expression in tumor cells, and potent tumoricidal activity.

Potent antitumor efficacy of an E1B 55kDa-deficient adenovirus carrying murine endostatin in hepatocellular carcinoma

Data from clinical trails have shown that the antitumoral effect of ONYX-015, an E1B 55kDa-deficient adenovirus, as monotherapy is insufficient. To enhance its efficiency, CNHK200-mE, another E1B 55kDa-deficient adenovirus armed with a mouse endostatin gene was constructed and its antitumoral activities against hepatocellular carcinoma (HCC) in vitro and in vivo were investigated. The selective replication and cytotoxicity of CNHK200-mE in Hep3B and HepGII cells independent of p53 status were confirmed via TCID50 and 3-(4,5dimetylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assays. Potent tumor growth suppression on SMMC-7721 xenografts in nude mice was observed and a synergistic effect of the carrier virus and the therapeutic gene was suggested. Moreover, in comparison with the nonreplicative adenovirus carrying the same therapeutic gene, amplified transgene expression of mouse endostatin in vitro and in vivo were confirmed by Western blotting and ELISA assay. The effective angiogenesis inhibition and replication of CNHK200-mE in nude mice xenografts were demonstrated by immunohistochemistry. In conclusion, the recombinant adenovirus CNHK200-mE is a replication-competent oncolytic virus mediating high expression of therapeutic gene. Because CNHK200-mE is capable of replicating in and lysing HCC cells selectively with effective tumor growth suppression and antiangiogenic activity on HCC xenografts in nude mice, it holds good potential for the treatment of HCC.

Effective gene-viral therapy for telomerase-positive cancers by selective replicative-competent adenovirus combining with endostatin gene

Gene-viral therapy, which uses replication-selective transgene-expressing viruses to manage tumors, can exploit the virtues of gene therapy and virotherapy and overcome the limitations of conventional gene therapy. Using a human telomerase reverse transcriptase-targeted replicative adenovirus as an antiangiogenic gene transfer vector to target new angiogenesis and making use of its unrestrained proliferation are completely new concepts in tumor management. CNHK300-mE is a selective replication transgene-expressing adenovirus constructed to carry mouse endostatin gene therapeutically. Infection with CNHK300-mE was associated with selective replication of the adenovirus and production of mouse endostatin in telomerase-positive cancer cells. Endostatin secreted from a human gastric cell line, SGC-7901, infected with CNHK300-mE was significantly higher than that infected with nonreplicative adenovirus Ad-mE in vitro (800 +/- 94.7 ng/ml versus 132.9 +/- 9.9 ng/ml) and in vivo (610 +/- 42 ng/ml versus 126 +/- 13 ng/ml). Embryonic chorioallantoic membrane assay showed that the mouse endostatin secreted by CNHK300-mE inhibited angiogenesis efficiently and also induced distortion of pre-existing vasculature. CNHK300-mE exhibited a superior suppression of xenografts in nude mice compared with CNHK300 and Ad-mE. In summary, we provided a more efficient gene-viral therapy strategy by combining oncolysis with antiangiogenesis.

Potent antitumoral efficacy of a novel replicative adenovirus CNHK300 targeting telomerase-positive cancer cells

PURPOSE

Telomerase reverse transcriptase (hTERT) is the key determinant of telomerase activity and plays a crucial role in cellular immortalization and oncogenesis. It will be a promising target for cancer gene therapy. We constructed a novel replicative adenovirus CNHK300 in which hTERT promoter with three extra E-boxes downstream of the promoter was introduced and used to regulate adenoviral E1a gene, and studied its properties of selective replication in cancer cells and antitumoral activity.

METHODS

Luciferase assay was used to detect hTERT promoter activity. The selective replication of CNHK300 in cancer cells was investigated by E1a Western blot and green fluorescent protein (GFP) reporter gene assay. The antitumoral activity of CNHK300 and its toxicity were measured on animal models.

RESULTS

Luciferase assay showed that introducing extra E-boxes downstream of hTERT promoter is beneficial to decreasing the promoter activity in normal cells without affecting its strong activity in cancer cells. Experiments in vitro and in vivo demonstrated that CNHK300 can selectively target to hTERT-positive cancer cells and replicate in them, resulting in oncolytic or antitumoral effect. CNHK300 is superior to ONYX-015 in terms of selective replication and oncolytic or antitumoral effect. The toxicity assay showed no signs of toxicity to liver cells even at the higher dosage of CNHK300 in vivo.

CONCLUSION

The hTERT promoter-controlled, replication-competent adenovirus CNHK300 is a promising system for targeted cancer gene therapy.

[Treatment of hepatocellular carcinoma with a novel gene-viral therapeutic system CNHK300-murine endostatin]

OBJECTIVE

To investigate the anti-tumor effects of a novel gene-viral therapeutic system CNHK300-murine endostatin (CNHK300-mE) in hepatocellular carcinoma (HCC).

METHODS

A novel gene-viral therapeutic system named CNHK300-mE was constructed by employing the human telomerase reverse transcriptase (hTERT) promoter to drive the expression of adenovirus E1A gene and cloning the therapeutic gene murine endostatin (mE) into the adenovirus genome. Hepatocellular cells of the HepGII and Hep3B lines and normal fibroblasts of the MRC-5 line were cultured and infected with the viruses CNHK300-mE, ONYX-015, replicative adenovirus without therapeutic gene, and Ad-mE, non-replicative adenovirus with the same therapeutic gene. Ninety-six hours after the infection, tissue culture infectious dose 50 method was used to detect the titer of virus in the supernatants. MTT method was used to examine the cytolytic capability. The expression of E1A and mE were examined by Western blotting. ELISA assay was used to detect the transgene expression of mouse endostatin. Healthy nude Balb/c mice were injected with hepatic cancer cells of the SMMC 7221 line. Forty mice with tumors 5 approximately 8 mm in diameter were randomly divided into 4 groups of 20 mice: CNHK300-mE group (CNHK300-mE was injected into the tumor once every other day for 5 times), Ad-mE group (Ad-mE was injected), ONYX-015group (ONYX-015 was injected), and control group (diluent of virus was injected). 3, 7, 14, 21, and 28 days after the initial injection the size of tumor was examined. 48 hours after the finish of the whole course of treatment, the mice were killed. ELISA was used to detect the expression of mE in blood. The growth of tumor was examined by HE staining, The angiogenesis in the tumor was observed by immunohistochemistry with von Willebrand factor and The proliferation of transplanted tumor was observed by immunohistochemistry with adenovirus envelop protein hexon.

RESULTS

Ninety-six hours after the infection of the cells by CNHK300-mE virus was replicated by 6329 +/- 1830 and 25 136 +/- 6890 times in the HepGII and Hep3B cells respectively, 3296 and 12 824 times higher than in the MRC-5 cells respectively. The replication multiples of ONYX-015 virus in the HepGII and Hep3B cells were 2040 +/- 450 and 3980 +/- 740 times respectively, both significantly lower than those of CNHK300-mE virus (both P < 0.05). However, no remarkable replication of Ad-mE virus was seen in the Western blotting showed the expression of therapeutic gene mE in HepGII and Hep3B cells infected with CNHK300-mE on Ad-mE. Hep3B cells, the band of CNHK300-mE being thicker than that of Ad-mE and the band of Ad-mE being similar to that of CNHK300-mE in the MRC-5 cells. ELISA showed that the expression of mE protein in the HepGII cells infected by CNHK300-mE virus increased time-dependently during the period of 7 days after virus infection, significantly higher than the expression in the HepGII cells infected by Ad-mE virus (P < 0.05). The tumors of the CNHK300-mE virus-infected mice were significantly smaller than those of the Ad-mE and ONYX-015-infected mice (both P < 0.01). ELISA showed that the mE protein content in the blood of the CNHK300mE-infected mice was significantly higher than that of the Ad-mE group (P < 0.05). Hexon immunohistochemistry showed patchy and diffuse positive staining related to apoptosis and necrosis of tumor cells in the transplanted tumors of the CNHK300-mE virus-infected mice, however, only sporadic positive staining was seen in the Ad-mE virus-infected mice.

CONCLUSION

Being capable of specifically replicating in the telomerase-positive HCC cells and mediating effective expression of therapeutic gene in vitro and in vivo, the novel gene-viral therapeutic system CNHK300-mE holds potential for treatment of HCC.

Chromosomal aberrations in esophageal squamous cell carcinoma among Chinese: gain of 12p predicts poor prognosis after surgery

Sixty primary esophageal squamous cell carcinomas (ESCCs) were evaluated for cytogenetic changes by comparative genomic hybridization (CGH). Recurrent chromosomal aberrations were correlated with stage and clinical outcome after esophagectomy to identify cytogenetic changes that are of prognostic significance. Chromosomal aberrations were found in 52 (86.7%) cases. The most frequently detected chromosomal gains involved 3q (67.3%), 8q (57.7%), 5p (51.9%), 7q (28.8%), 15q (28.8%), 20p (21.2%), 20q (28.8%), 1q (26.9%), 7p (26.9%), 2p (23.1%), and 12p (23.1%). Chromosome 12p was most frequently involved in high-level amplification. Six of the 12 cases with gain in 12p showed high-level amplification and the minimum overlapping region localized to 12pter-p13. The most frequently detected chromosomal loss involved 3p (46.2%), 4q (26.9%), 4p (23.1%), 3q (19.2%), 9p (17.3%), 19p (17.3%), and whole 13 (15.4%). No significant correlation was found between the recurrent chromosomal aberrations and pathological stage of ESCC. Univariate analysis demonstrated that late pathological stage (III and IV), gain in 12p, and loss in 3p are associated with poor relapse-free survival. Multivariate analysis confirmed gain in 12p as independent prognosticator for relapse-free survival after esophagectomy besides pathological stage. We conclude that chromosomal aberrations are common in ESCC. Gain in 12p is indicative of poor prognosis after esophagectomy, and combined modality therapy would be indicated in these patients.

Detection of wild type and deleted latent membrane protein 1 (LMP1) of Epstein-Barr virus in clinical biopsy material

The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) is one of two postulated viral oncogenic proteins. Sequence variations, and in particular a 30 base pair deletion variant called CAO, may define different disease populations. We developed a panel of rat monoclonal antibodies (MAb) specific for the non-wild type LMP1 and compared the presence of the antibody staining with LMP1 DNA sequence analysis on clinical samples of nasopharyngeal carcinoma, peripheral T-cell lymphoma (PTCL), Hodgkin's disease, lymphoblastoid cell lines (LCL) from normal volunteers, and patients with nasopharyngeal carcinoma. The results demonstrate specificity of the monoclonal cocktail for detecting the non-wild type LMP1 and the ability to sub-differentiate between the mediterranean type of LMP1 and the CAO-LMP1. Double immunofluorescence on paraffin material using the traditional CS1-4 monoclonal antibodies and the CAO-cocktail revealed no dual population of cells in the biopsy material from the Asian region.

Classification of in vivo autofluorescence spectra using support vector machines

An algorithm based on support vector machines (SVM), the most recent advance in pattern recognition, is presented for use in classifying light-induced autofluorescence collected from cancerous and normal tissues. The in vivo autofluorescence spectra used for development and evaluation of SVM diagnostic algorithms were measured from 85 nasopharyngeal carcinoma (NPC) lesions and 131 normal tissue sites from 59 subjects during routine nasal endoscopy. Leave-one-out cross-validation was used to evaluate the performance of the algorithms. An overall diagnostic accuracy of 96%, a sensitivity of 94%, and a specificity of 97% for discriminating nasopharyngeal carcinomas from normal tissues were achieved using a linear SVM algorithm. A diagnostic accuracy of 98%, a sensitivity of 95%, and a specificity of 99% for detecting NPC were achieved with a nonlinear SVM algorithm. In a comparison with previously developed algorithms using the same dataset and the principal component analysis (PCA) technique, the SVM algorithms produced better diagnostic accuracy in all instances. In addition, we investigated a method combining PCA and SVM techniques for reducing the complexity of the SVM algorithms.

Laboratory markers of tumor burden in nasopharyngeal carcinoma: A comparison of viral load and serologic tests for Epstein-Barr virus

Epstein-Barr virus (EBV) is present within the tumor cells of most cases of nasopharyngeal carcinoma (NPC). Recent studies suggest that tumor burden is proportional to the level of EBV DNA in blood and that rapid blood testing can be used to guide therapeutic intervention. The relative utility of viral load vs. serology has been insufficiently studied. In our study, EBV viral load was measured by quantitative PCR using either real-time or end-point detection systems in serum samples from 124 NPC patients (93 pretreatment, 13 relapsed, 18 in remission) and 40 controls. Serologic titers against EBV early antigen were measured in the same serum samples. EBV DNA was detectable in 64 of 93 untreated NPC patients (69%; mean viral load 11,211 copies/ml), 11 of 13 relapsed NPC patients (85%; mean 53,039 copies/ml) and 0 of 18 remission patients. EBV DNA was detectable in only 1 of 40 non-NPC controls (3%). In 34 instances where paired plasma and serum samples were available for testing, both were effective sample types, and there was no significant difference between end-point and real-time methods for measuring viral load. Early antigen (EA) IgA and IgG titers were elevated in most NPC patients regardless of whether their disease was active or in remission. EBV viral load was more informative than was EA serology for distinguishing remission from relapsed disease. EBV DNA measurement appears to be a noninvasive way to monitor tumor burden after therapy.

Gene-viral vectors: a promising way to target tumor cells and express anticancer genes simultaneously

OBJECTIVE

To develop a new kind of vector system called gene-viral vector, which combines the advantages of gene and virus therapies.

METHODS

Using recombinant technology, an anti-tumor gene was inserted into the genome of replicative virus specific for tumor cells. The cell killing effect, reporter gene expression of the green fluorescence protein, anti-tumor gene expression of mouse interleukin-12 (mIL-12) and replication of virus were observed by the methods of cell pathology, fluorescence microscopy, ELISA and electron microscopy, respectively.

RESULTS

A new kind of gene-viral vector system of adenovirus, in which the E1b-55 kD gene was deleted but the E1a gene was preserved, was constructed. The vector system, like the replicative virus ONYX-015, replicated and proliferated in tumor cells but not in normal ones. Our vector had an advantage over ONYX-015 in that it carried different kinds of anti-tumor genes to enhance its therapeutic effect. The reporter gene expression of the green fluorescence protein in tumor cells was much better than the adenovirus vector employed in conventional gene the rapy, and the expression in our vector system was as low as or even less than that in the conventional adenovirus gene therapy system. Similar results were observed in experiments with this vector system carrying the anti-tumor gene mIL-12. Replication and proliferation of the virus carrying the mIL-12 gene in tumor cells were confirmed by electron microscopy.

CONCLUSIONS

Gene-viral vectors are new vectors with an anti-tumor gene inserted into the genome of replicative virus specific for tumor cells. Because of the specific replication and proliferation of the virus in tumor cells, expression of the anti-tumor gene is increased hundreds to thousands of times. This approach takes full advantages of gene therapy and virus therapy to enhance the effect on the tumor. It overcomes the disadvantages of conventional gene therapy, such as low transfer rate, low gene expression, lack of target tropism, and low anti-tumor activity. We believe that this is a promising means for future tumor treatment.

Epidermal growth factor improves nutritional outcome in a rat model of short bowel syndrome

BACKGROUND/PURPOSE

This study investigates the effect of epidermal growth factor (EGF) on nutrient absorption in a rat model of short bowel syndrome (SBS).

METHODS

Male juvenile rats underwent either transection (Sham) or ileocecal resection leaving a 20-cm jejunal remnant. Animals underwent follow-up for 10 days, and resected animals were treated with placebo or recombinant human EGF (1-53). Animals were pair fed; in vivo nutrient absorption, intestinal permeability, morphology, and total intestinal DNA and protein content were measured.

RESULTS

Resected EGF-treated animals lost significantly less weight than those in the placebo group (-4.2 +/- 3 v -13.7 +/- 6.9%), absorbed significantly more 3-0 methylglucose (76.8 +/- 6.6 v 64.9 +/- 10.1%), and had reduced permeability (lactulose/mannitol ratio, 0.35 +/- 0.19 v 0.60 +/- 0.20; P <.05 for all comparisons).

CONCLUSIONS

These findings show that treatment of short bowel syndrome animals with EGF reduced weight loss and improved carbohydrate absorption and intestinal permeability. These findings suggest that enteral EGF may be a useful therapy for short bowel syndrome; further studies are indicated.

[High-level mIL-12 expression and replication of replicating adenovirus carrying mIL12 gene in naso-pharyngeal carcinoma cells]

OBJECTIVE

To enhance the therapeutic effects on nasopharyngeal carcinoma by combining treatment with selectively replicating adenovirus and IL12.

METHODS

Replicating adenovirus with mouse IL12 gene insert (CNHK200-mIL12) was constructed to transfect nasopharyngeal carcinoma cell lines CNE3 and 915. Adenovirus hexon was detected by immunohistochemical staining and flow cytometry (FCM), and mIL12 expression examined by enzyme-linked immunosorbent assay (ELISA). The replication rates of CNHK200-mIL12 and dl1520 was determined by 50% tissue culture infectious dose (TCID50).

RESULTS

Twenty-four hours after transfection with CNHK200-mIL12, most of cells were positive for adenovirus hexon and FCM demonstrated increased positivity rates of 39% and 4% among CNE3 and 915 cells respectively. It was observed that CNHK200-mIL12 replication increased by 1 000 folds with mIL12 expression level reaching as high as 84.5+/-4.6 ng in CNE3 cells and 75.6+/-3.4 ng in 915 cells as determined 72 h after transfection with 1x10(5) PFU CNHK200-mIL12 into 1x10(4) cells.

CONCLUSION

CNHK200-mIL12 can replicate in vitro in nasopharyngeal carcinoma cells (dl1520 cells, for instance) with high mIL12 expression, which suggests that CNHK200-mIL12 may potentially be used to treat nasopharyngeal carcinoma.

Comparative analysis of the expression of the Epstein-Barr virus (EBV) anti-apoptotic gene BHRF1 in nasopharyngeal carcinoma and EBV-related lymphoid diseases

Epstein-Barr virus (EBV) has been identified in a wide range of neoplastic and non-neoplastic disorders. The EBV open reading frame BHRF1 encodes a protein with partial sequence and functional homology to the anti-apoptotic onco-protein Bcl-2 and may therefore have a role in the proliferation of EBV positive cells. We have developed a rat monoclonal antibody against pBHRF1, which can detect BHRF1 in paraffin sections. While a number of mutant versions of BHRF1 were recognised, the monoclonal did not detect the BHRF1 homologue encoded by Herpesvirus papio or two mutants with deletions in the BH2 region. This novel rat monoclonal antibody (6A9) was used to examine tissue sections from 39 cases of non-keratinising undifferentiated nasopharyngeal carcinoma (NPC), 6 cases of metastatic NPC, 7 cases of EBV-positive NPC with squamous differentiation from Chinese patients, 15 cases of EBV-positive post-transplant lymphoproliferative disorder (PTLD), 6 EBV-containing lymphoblastoid cell lines, and 2 cases of oral hairy leukoplakia (OHL). In 11 cases of undifferentiated NPC, RT-PCR data were available for comparison with the immunohistochemistry. Both cases of OHL and two cases of LCL were positive for BHRF1 but none of the PTLD showed positive staining. All cases of undifferentiated NPC were positive for Bcl-2 but only one BHRF1 positive cell was identified in 1 of 39 cases of primary undifferentiated NPC. The 6A9 antibody produced less background staining and no nuclear positivity compared with the commercially available mouse monoclonal 5B11. It is concluded that BHRF1 can not be detected by immunohistochemistry in NPC and therefore it appears not to play a significant anti-apoptotic role in the progression of this EBV-associated tumour. The 6A9 monoclonal appears to be superior to 5B11 for the detection of pBHRF1 in tissue sections.

Microsatellite allelotyping of chinese nasopharyngeal carcinomas

BACKGROUND

Chinese nasopharyngeal carcinoma (NPC) specimens were analyzed by microsatellite allelotyping to evaluate their usefulness as biomarkers for cancer detection.

MATERIALS AND METHODS

A panel of eight microsatellite markers localized to chromosomes 3p, 6p, 9p, I1q and 14q were used to study 47 specimens.

RESULTS

A moderately low loss of heterozygosity (LOH) frequency (8% to 35%) was observed; 23 (49%) specimens showed LOH with at least one marker while microsatellite instability (MSI) was detected in 10 specimens (21%).

CONCLUSION

Poor survival was significantly associated with LOH detected by a chromosome 3 marker. Interestingly, tumors with multiple genetic alterations were significanty associated with earlier staging

Analysis of genetic alterations in primary nasopharyngeal carcinoma by comparative genomic hybridization

To identify genetic alterations associated with the development and progression of human nasopharyngeal carcinoma (NPC), 57 tumors were analyzed by comparative genomic hybridization (CGH). In 47 cases, chromosomal imbalances were found. Several recurrent chromosomal abnormalities were identified in the present study. The most frequently detected chromosomal gains involved chromosome arms 12q (24 cases, 51%), 4q (17 cases, 36%), 3q (16 cases, 34%), 1q (15 cases, 32%), and 18q (15 cases, 32%). Common regions of gain involved 12q13--q15, 4q12--q21, and 3q21--q26. High-copy-number increases of chromosomal materials were detected in four chromosomal regions, 3q21--q26.2, 4p12--q21, 8p, and 12q14--q15. The most frequently detected loss of chromosomal materials involved chromosome arms 16q (26 cases, 55%), 14q (21 cases, 45%), 1p (20 cases, 43%), 3p (20 cases, 43%), 16p (19 cases, 40%), 11q (17 cases, 36%), and 19p (16 cases, 34%). The most common regions of loss involved 14q24--qter, 1pter--p36.1, 3p22--p21.3, 11q21--qter, and the distal region of 19p. Genomic alterations detected by CGH were compared and found to be largely consistent with those identified in banding analysis and loss of heterozygosity studies. However, several previously unrecognized recurrent alterations were also identified in the present study, including gain of 4q and 18q, and loss of 16q, 14q, and 19p. In addition, gain of 1q, 8q, 18q, and loss of 9q showed a statistically significant association with advanced clinical stages (P < 0.05). Identification of recurrent sites of chromosomal gain and loss identify regions of the genome that may contain oncogenes or tumor suppressor genes, respectively, which may be involved in the tumorigenesis of NPC. Published 2000 Wiley-Liss, Inc.

Analysis of genetic alterations in primary nasopharyngeal carcinoma by comparative genomic hybridization

To identify genetic alterations associated with the development and progression of human nasopharyngeal carcinoma (NPC), 57 tumors were analyzed by comparative genomic hybridization (CGH). In 47 cases, chromosomal imbalances were found. Several recurrent chromosomal abnormalities were identified in the present study. The most frequently detected chromosomal gains involved chromosome arms 12q (24 cases, 51%), 4q (17 cases, 36%), 3q (16 cases, 34%), 1q (15 cases, 32%), and 18q (15 cases, 32%). Common regions of gain involved 12q13--q15, 4q12--q21, and 3q21--q26. High-copy-number increases of chromosomal materials were detected in four chromosomal regions, 3q21--q26.2, 4p12--q21, 8p, and 12q14--q15. The most frequently detected loss of chromosomal materials involved chromosome arms 16q (26 cases, 55%), 14q (21 cases, 45%), 1p (20 cases, 43%), 3p (20 cases, 43%), 16p (19 cases, 40%), 11q (17 cases, 36%), and 19p (16 cases, 34%). The most common regions of loss involved 14q24--qter, 1pter--p36.1, 3p22--p21.3, 11q21--qter, and the distal region of 19p. Genomic alterations detected by CGH were compared and found to be largely consistent with those identified in banding analysis and loss of heterozygosity studies. However, several previously unrecognized recurrent alterations were also identified in the present study, including gain of 4q and 18q, and loss of 16q, 14q, and 19p. In addition, gain of 1q, 8q, 18q, and loss of 9q showed a statistically significant association with advanced clinical stages (P < 0.05). Identification of recurrent sites of chromosomal gain and loss identify regions of the genome that may contain oncogenes or tumor suppressor genes, respectively, which may be involved in the tumorigenesis of NPC. Published 2000 Wiley-Liss, Inc.

Preliminary study of in vivo autofluorescence of nasopharyngeal carcinoma and normal tissue

BACKGROUND AND OBJECTIVE

In nasopharyngeal cancer, conventional white light endoscopy does not provide adequate information to detect the flat/small lesion and identify the margin of observable tumor. In the present study, we evaluate the potential of light-induced fluorescence spectroscopic imaging for the localization of cancerous nasopharyngeal tissue.

STUDY DESIGN/MATERIALS AND METHODS

We built a multiple channel spectrometer specifically for the investigation of fluorescence collected by a conventional endoscopic system. Nasopharyngeal fluorescence were measured in vivo from 27 subjects during the routine endoscopy. The biopsy specimens for histologic analysis were taken from the tissue sites where the fluorescence were measured.

RESULTS

Two algorithms to discriminate the nasopharyngeal carcinoma from normal tissue were created based on the good correlation between the tissue autofluorescence and histologic diagnosis. For the two-wavelength algorithm, carcinoma can be differentiated from normal tissue with a sensitivity and specificity of 93% and 92%, respectively. For the three-wavelength algorithm with compensation of variation of blood content in tissue, a sensitivity of 98% and specificity of 95% were achieved.

CONCLUSION

Fluorescence endoscopic imaging used with the algorithms developed in this report is an efficient method for detecting the nasopharyngeal carcinoma.