Association of ICAM3 genetic variant with severe acute respiratory syndrome

Genetic polymorphisms have been demonstrated to be associated with vulnerability to human infection. ICAM3, an intercellular adhesion molecule important for T cell activation, and FCER2 (CD23), an immune response gene, both located on chromosome 19p13.3, were investigated for host genetic susceptibility and association with clinical outcome. A case-control study based on 817 patients with confirmed severe acute respiratory syndrome (SARS), 307 health care worker control subjects, 290 outpatient control subjects, and 309 household control subjects unaffected by SARS from Hong Kong was conducted to test for genetic association. No significant association to susceptibility to SARS infection caused by the novel coronavirus (SARS-CoV) was found for the FCER2 and the ICAM3 single nucleotide polymorphisms. However, patients with SARS homozygous for ICAM3 Gly143 showed significant association with higher lactate dehydrogenase levels (P = .0067; odds ratio [OR], 4.31 [95% confidence interval {CI}, 1.37-13.56]) and lower total white blood cell counts (P = .022; OR, 0.30 [95% CI, 0.10-0.89]) on admission. These findings support the role of ICAM3 in the immunopathogenesis of SARS. © 2007 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio

Cancer Genomics Identifies Regulatory Gene Networks Associated with the Transition from Dysplasia to Advanced Lung Adenocarcinomas Induced by c-Raf-1

Background: Lung cancer is a leading cause of cancer morbidity. To improve an understanding of molecular causes of disease a transgenic mouse model was investigated where targeted expression of the serine threonine kinase c-Raf to respiratory epithelium induced initialy dysplasia and subsequently adenocarcinomas. This enables dissection of genetic events associated with precancerous and cancerous lesions. Methodology/Principal Findings: By laser microdissection cancer cell populations were harvested and subjected to whole genome expression analyses. Overall 473 and 541 genes were significantly regulated, when cancer versus transgenic and non-transgenic cells were compared, giving rise to three distinct and one common regulatory gene network. At advanced stages of tumor growth predominately repression of gene expression was observed, but genes previously shown to be upregulated in dysplasia were also up-regulated in solid tumors. Regulation of developmental programs as well as epithelial mesenchymal and mesenchymal endothelial transition was a hall mark of adenocarcinomas. Additionaly, genes coding for cell adhesion, i.e. the integrins and the tight and gap junction proteins were repressed, whereas ligands for receptor tyrosine kinase such as epi- and amphiregulin were up-regulated. Notably, Vegfr- 2 and its ligand Vegfd, as well as Notch and Wnt signalling cascades were regulated as were glycosylases that influence cellular recognition. Other regulated signalling molecules included guanine exchange factors that play a role in an activation of the MAP kinases while several tumor suppressors i.e. Mcc, Hey1, Fat3, Armcx1 and Reck were significantly repressed. Finally, probable molecular switches forcing dysplastic cells into malignantly transformed cells could be identified. Conclusions/Significance: This study provides insight into molecular pertubations allowing dysplasia to progress further to adenocarcinoma induced by exaggerted c-Raf kinase activity

Mitomycin C and cisplatin enhanced the antitumor activity of p53-expressing adenovirus in cervical cancer cells

This study investigated the enhanced antitumor activity of Ad5-p53 in combination with mitomycin C (MMC) or cisplatin (DDP) in cervical cancer cell lines SiHa and C-33A. MMC and DDP inhibited the growth of SiHa and C-33A cells in a dose-dependent manner, and the combination of MMC or DDP with Ad5-p53 showed a stronger growth inhibition than those treated with either Ad5-p53, MMC, or DDP alone. As evidenced by the formation of the ∼200 bp DNA ladder and the appearance of sub-G1 peak both MMC and DDP induced apoptosis in cervical cancer cells. Western blot analysis of p53 showed that MMC/DDP did not induce the increase of p53 protein in SiHa cells nor the increase of the cellular and nuclear p53 protein in Ad5-p53 transfected Saos-2 cells. Taken together, these results suggested that the combination of Ad5-p53 and MMC/DDP may serve as an effective therapeutic regime for human cervical cancer treatment.link_to_subscribed_fulltex

Changes in p21(WAF1), pRb, Mdm-2, Bax and Bcl-2 expression in cervical cancer cell lines transfected with a p53 expressing adenovirus

The aim of this study was to provide some insights into the molecular mechanisms involved in p53-dependent apoptosis and growth arrest. Changes in the levels of p53 protein and proteins regulated by p53 were studied in relation to events of the cell cycle and apoptosis in cervical cancer cell lines upon transfection with a p53 expressing adenovirus (Ad5-p53). The post- transfection level of p53 protein in SiHa cells was found to be unchanged during the 24-48 h period. In contrast, the level of p21(WAF1) protein was shown to increase to its highest level at 24 h, and decreased gradually up to 48 h after the Ad5-p53 transfection. We further noted that the increase of p21(WAF1) was accompanied by G1 arrest at 24 h and the decrease of p21(WAF1) was associated with apoptosis at 36-48 h after transfection. An anti- p21(WAF1) antibody cross-reactive protein band of approximately 14 kDa was observed in HeLa and C-33A cells when these cells were committed to apoptosis upon Ad5-p53 transfection. In SiHa cells, phosphorylation of pRb was inhibited during the early stage of Ad5-p53 transfection. This was followed by the cleavage of pRb. However, Ad5-p53 transfection did not change the levels of Bax and Bcl-2 proteins. Our results suggested that, Bax and Bcl-2 may not be important for the apoptosis of these cells, whereas cleavage of Rb, and the decrease of p21(WAF1) could play important roles in p53-dependent apoptosis. (C) 2000 Elsevier Science Ltd.link_to_subscribed_fulltex

pRb-expressing adenovirus Ad5-Rb attenuates the p53-induced apoptosis in cervical cancer cell lines

The retinoblastoma protein (pRb), the gene product of the first reported tumour suppressor gene, is functionally inactivated by the E7 protein of high-risk human papillomavirus (HPV) found in most human cervical cancers. We have, in this study, constructed an adenoviral vector expressing wild-type pRb (Ad5-Rb) and used the constructed Ad5-Rb to transfect the osteosarcoma cell line Saos-2, and three cervical cancer cell lines HeLa, SiHa and C-33A. Our results showed that pRb caused G1 arrest in Saos-2 cells after transfection with Ad5-Rb. The number of colonies formed by the Ad5-Rb-transfected Saos-2 cells in soft agar was also found to be significantly lower (P < 0.05) than those transfected with the adenoviral control expressing Escherichia coli β-galactosidase (Ad5-LacZ). The transfection of Ad5-Rb caused an increase in the population of SiHa and C-33A cells in the G1 phase from 53.0 and 52.9% to 72.4 and 64.3%, respectively, but not in the HeLa cells. However, Ad5-Rb did not show any inhibitory effect on the growth of SiHa, HeLa and C-33A cells, and inhibition of colony formation in soft agar was not observed either. In contrast, flow cytometric analysis showed that Ad5-p53, a p53-expressing adenovirus, induced apoptosis, i.e. the appearance of sub-G1 peak, in all three tested cervical cancer cell lines. Nevertheless, the Ad5-p53-induced apoptosis was partially inhibited when Ad5-Rb was added simultaneously. These findings suggested that pRb may not be a good candidate for cervical cancer gene therapy. Our data also showed that the use of full-length pRb in combination with TP53 might not be a suitable strategy for cancer gene therapy. © 2001 Elsevier Science Ltd. All rights reserved.link_to_subscribed_fulltex

Single-dose methotrexate regimen in the treatment of low-risk gestational trophoblastic neoplasia

Objective: The objective of the study was to evaluate the effectiveness of single-dose methotrexate in women with low-risk gestational trophoblastic neoplasia. Study design: In this prospective observational cohort study, 105 women with low-risk gestational trophoblastic neoplasia were treated with an intravenous bolus of 100 mg/m2 of methotrexate followed by a 12-hour infusion of 200 mg/m2. If the human chorionic gonadotropin level fell 10-fold after 2 weeks, no further chemotherapy was given. Characteristics between the 2 groups with or without complete remission with this regimen were compared. Results: The overall complete remission rate with methotrexate was 84.8%, with 44.8% of women requiring a single dose of methotrexate alone. The pretreatment human chorionic gonadotropin level was found to be significantly higher in women who failed the single-dose methotrexate regimen (P = .001), and 10 of 11 patients with metastases required further doses. Conclusion: This regimen offers an effective option for women with low-risk gestational trophoblastic neoplasia without metastases and a low pretreatment human chorionic gonadotropin level. © 2006 Mosby, Inc. All rights reserved.link_to_subscribed_fulltex

Genetic abnormalities and HPV status in cervical and vular squamous cell carcinomas

Cervical and vulvar cancers are diseases of the female lower genital tract, and high-risk human papillomavirus (HPV) infection is the most important risk factor for the development of both cancers. However, it is clear that additional genetic events are necessary for tumor progression, particularly in HPV-negative cases. We detected the presence of high-risk HPV16 and HPV18 genomes by gene-specific polymerase chain reaction and searched for common genetic imbalances by comparative genomic hybridization (CGH) in 28 cervical and 8 vulvar tumor samples and 7 cancer cell lines. The presence of the HPV genome was detected in 25/28 (89%) cervical tumors and 6/8 (75%) vulvar tumors. CGH of cervical and vulvar tumor samples revealed a consistent pattern of genetic changes in both cancers. Frequent gains were found in 1q, 3q, 5p, and 8q, and less consistent losses were detected in 2q, 3p, 4p, and 11p. Notably, a high-level amplification of 3q was found in 9/28 (32%) cervical tumors and 1/8 (12.5%) vulvar tumors, indicating a pivotal role of gain of 3q in cervical and vulvar carcinogenesis. Furthermore, gains of 5p identified in 9/28 (32%) cervical tumors and 3/8 (37.5%) vulvar tumors were seldom described, particularly in vulvar tumors. Our findings suggest that cervical and vulvar carcinomas bear similar chromosomal alteration hot spots that largely coincide with common genomic lesions during tumor progression, besides the initiation by infection and integration of oncogenic HPV. © 2005 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

Genetic abnormalities and HPV status in cervical and vulvar squamous cell carcinomas

Cervical and vulvar cancers are diseases of the female lower genital tract, and high-risk human papillomavirus (HPV) infection is the most important risk factor for the development of both cancers. However, it is clear that additional genetic events are necessary for tumor progression, particularly in HPV-negative cases. We detected the presence of high-risk HPV16 and HPV18 genomes by gene-specific polymerase chain reaction and searched for common genetic imbalances by comparative genomic hybridization (CGH) in 28 cervical and 8 vulvar tumor samples and 7 cancer cell lines. The presence of the HPV genome was detected in 25/28 (89%) cervical tumors and 6/8 (75%) vulvar tumors. CGH of cervical and vulvar tumor samples revealed a consistent pattern of genetic changes in both cancers. Frequent gains were found in 1q, 3q, 5p, and 8q, and less consistent losses were detected in 2q, 3p, 4p, and 11p. Notably, a high-level amplification of 3q was found in 9/28 (32%) cervical tumors and 1/8 (12.5%) vulvar tumors, indicating a pivotal role of gain of 3q in cervical and vulvar carcinogenesis. Furthermore, gains of 5p identified in 9/28 (32%) cervical tumors and 3/8 (37.5%) vulvar tumors were seldom described, particularly in vulvar tumors. Our findings suggest that cervical and vulvar carcinomas bear similar chromosomal alteration hot spots that largely coincide with common genomic lesions during tumor progression, besides the initiation by infection and integration of oncogenic HPV. © 2005 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

Semi-quantitative fluorescent PCR analysis identifies PRKAA1 on chromosome 5 as a potential candidate cancer gene of cervical cancer

Objective.: Comparative genomic hybridization has frequently detected amplification of chromosome 5p in cervical cancer, but candidate cancer genes within the region are rarely known. Therefore, we pursued to identify potential candidate gene related to cervical cancer development. Methods.: A series of 128 cervical tumor samples were examined by semi-quantitative fluorescent differential PCR for copy number changes on three candidate genes (PRKAA1, CTNND2 and POLS) mapped to chromosome 5p and one gene (ERBIN) mapped to chromosome 5q12.3. The impact of gene copy number was later analyzed in relation to HPV infection, tumor stage or tumor radiosensitivity. Results.: DNA copy numbers of PRKAA1, CTNND2 and ERBIN were significantly different from normal controls (P < 0.05). DNA copy number changes did not correlate with HPV infection, tumor stages or tumor radiosensitivity. Using RT-PCR, PRKAA1 mRNA expression in seven tumor samples with known 5p amplification was amplified from 3- to 15-fold. Over-expression of PRKAA1 was further confirmed by immunohistochemical staining on 125 paraffin-embedded cervical cancer tissues. The expression level in cervical tumor was significantly higher than that in normal epithelium (P < 0.001). Conclusions.: PRKAA1 gene codes for the catalytic alpha 1 subunit of the AMP-activated protein kinase which is an important cellular metabolic stress regulator. It might assist tumor cells growth under stress. Thus, PRKAA1 may be one of the potential candidate genes for cervical carcinogenesis. © 2006 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex