| 91. |
|
|
| 92. |
|
|
| 93. |
- Zhang, Hong, 1957-, et al.
(författare)
-
Expression profiles of Id1 and p16 proteins in all-trans-retinoic acid-induced apoptosis and cell cycle re-distribution in melanoma
- 2005
-
Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 217:1, s. 33-41
-
Tidskriftsartikel (refereegranskat)abstract
- All-trans-retinoic acid (atRA) exerts its effects via apoptosis and cell cycle re-distribution. However, the mechanisms behind the effects have not been fully understood. In this study, we used a model system of matched primary and metastatic melanoma cells to investigate whether expression of Id1 and p16 proteins were involved in atRA-induced apoptosis and cell cycle re-distribution. Melanoma cells were exposed to 0.1 or 10 μM atRA for 1-96 h. Apoptosis and cell cycle were measured by flow cytometry. Expression of Id1 and p16 proteins was examined by Western blotting and immunocytochemistry. After exposure to atRA we found a marked increase in apoptosis and cell cycle re-distribution in both primary and metastatic melanoma cells. Expression level of Id1 protein was decreased and the p16 was increased in a dose- and time-dependent (P<0.05) manner after treatment with atRA. Alterations of these proteins were more pronounced in the primary melanoma cells than the matched metastases (P<0.05). These data suggested that the alterations of Id1 and/or p16 proteins were involved in atRA-induced apoptosis and cell cycle re-distribution in melanoma. These expression profiles of Id1 and p16 proteins may provide molecular evidence for better chemotherapy primarily for early stages of melanoma.
|
|
| 94. |
- Zhang, Hong, 1957-
(författare)
-
p53 plays a central role in UVA and UVB induced cell damage and apoptosis in melanoma cells
- 2006
-
Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 244:2, s. 229-238
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated whether p53 plays a role in UV induced apoptosis in melanoma. UVA and UVB induced apoptosis in dose dependent and wild type p53 melanoma cells were much more vulnerable than the mutant cells, indicating that p53 played a role in UV-induced apoptosis in melanoma. No difference in p53 expression pattern between the primary and matched metastatic melanomas was noticed in tumour tissue or cell lines from the same patients. Our findings indicate that expression of p53 plays a role in UV-induced apoptosis in melanoma cells, but not important in melanoma progression from primary to metastasis. © 2006 Elsevier Ireland Ltd. All rights reserved.
|
|
| 95. |
- Zhang, Hao, et al.
(författare)
-
Papillomavirus type 16 E6/E7 and human telomerase reverse transcriptase in esophageal cell immortalization and early transformation
- 2007
-
Ingår i: Cancer Letters. - : Elsevier BV. - 1872-7980 .- 0304-3835. ; 245:1-2, s. 184-194
-
Tidskriftsartikel (refereegranskat)abstract
- Infection with high-risk human papillomavirus (HPV) has been implicated in the pathogenesis of esophageal squamous cell carcinoma, and up-regulation of telomerase in esophageal adenocarcinoma. We immortalized normal esophageal epithelial cells by over-expression of the HPV16 E6/E7 and human telomerase reverse transcriptase (hTERT) genes. HPV16 E6/E7-induced immortalization was accompanied by reduced RB and p53, but increased p16 and p21, protein expression. hTERT-immortalized cells had unaffected RB and p53, but significantly decreased p16 and p21, protein expression. Aurora-A protein was also upregulated in E6E7 immortalized cells, and to a less extent in hTERT immortalized cells. Fluorescence in situ hybridization showed that the Aurora-A gene locus was amplified in E6E7 immortalized cells, which might account in part for the Aurora-A overexpression. These molecular changes led to an abrogation of the G2 checkpoint. E6E7 and hTERT immortalized esophageal cells recapitulated many of the molecular changes observed in esophageal carcinomas, where RB and p53 are frequently downregulated. However, down-regulation of p16 and p21 occurred frequently in esophageal cancer, owing to aberrant gene promoter methylation. We showed in the immortalized cells that aberrant methylation had not yet set in, suggesting that promoter methylation might not be necessary for cellular immortalization. In addition to supporting the role of HPV and telomerase in esophageal carcinogenesis, our cell lines may also be useful in vitro models for further studies of esophageal carcinogenesis.
|
|
| 96. |
- Zhang, Jiao, et al.
(författare)
-
Wnt inhibitory factor-1 functions as a tumor suppressor through modulating Wnt/β-catenin signaling in neuroblastoma
- 2014
-
Ingår i: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 348:1–2, s. 12-19
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is the most common extracranial solid tumor in childhood and is associated with serious morbidity and mortality. The effective treatment of neuroblastoma remains one of the major challenges in pediatric oncology. The Wnt signaling pathway has been shown to play a significant role in the pathogenesis of adult and pediatric tumors. WIF-1 has been identified as an important Wnt antagonist which inhibits Wnt/β-catenin signaling by directly binding to Wnt proteins. However, the expression and function of WIF-1 in neuroblastoma remains unknown. The present study showed that WIF-1 was downregulated with high level promoter methylation in neuroblastoma cells, and was significantly upregulated after exposure to demethylating agent. This finding suggests that downregulation of WIF-1 was associated with its promoter methylation in neuroblastoma. To further study the potential function of WIF-1 in neuroblastoma, we constructed a plasmid that over-expressed WIF-1 and transfected the plasmid into one neuroblastoma cell line SK-N-SH. We found that restoration of WIF-1 inhibited the growth and proliferation of neuroblastoma cells in vitro. Morever, Wnt/β-catenin signaling activity and target genes expression were reduced by WIF-1 restoration. These results provide support that WIF-1 is downregulated and functions as a tumor suppressor by antagonizing Wnt/β-catenin signaling in neuroblastoma, suggesting a potential role as a therapeutic target in neuroblastoma.
|
|
| 97. |
- Zhang, Zhi-Jia, et al.
(författare)
-
Synergistic inhibitory effects of interferon-alpha and 5-fluorouracil on human meningeoma cells in vitro
- 1996
-
Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 100:1-2, s. 99-105
-
Tidskriftsartikel (refereegranskat)abstract
- We have investigated the effects of interferon-α (IFN-α) and 5-fluorouracil (5-FU) on meningioma cells in two different culture systems, evaluated by the uptake of radiolabelled methionine. With both IFN-α and 5-FU an inhibitory effect on the uptake of radiolabelled methionine by the meningioma cells was demonstrated, and we found a synergistic inhibitory effect with a combination of IFN-α and 5-FU. To obtain a maximal inhibition of cell metabolism without causing cell toxicity, we were able to decrease the dose of 5-FU by simultaneously adding IFN-α. Our results suggest that a combined treatment of IFN-α and 5-FU may be a successful alternative for patients with inoperable meningiomas. A novel in vitro positron emission tomography technique was used for the study of metabolic changes in tumour cells caused by drug treatment, which is complementary to conventional cell culture techniques.
|
|
| 98. |
- Zheng, Daoshan, et al.
(författare)
-
Regulation of sex hormone receptors in sexual dimorphism of human cancers
- 2018
-
Ingår i: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 438, s. 24-31
-
Forskningsöversikt (refereegranskat)abstract
- Gender differences in the incidences of cancers have been found in almost all human cancers. However, the mechanisms that underlie gender disparities in most human cancer types have been under-investigated. Here, we provide a comprehensive overview of potential mechanisms underlying sexual dimorphism of each cancer regarding sex hormone signaling. Fully addressing the mechanisms of sexual dimorphism in human cancers will greatly benefit current development of precision medicine. Our discussions of potential mechanisms underlying sexual dimorphism in each cancer will be instructive for future cancer research on gender disparities.
|
|
| 99. |
- Zhuang, Shi-Mei, 1965-, et al.
(författare)
-
Mutation analysis of the pRb pathway in 2',3'-dideoxycytidine- and 1,3-butadiene-induced mouse lymphomas
- 2000
-
Ingår i: Cancer Letters. - 0304-3835 .- 1872-7980. ; 152:2, s. 129-134
-
Tidskriftsartikel (refereegranskat)abstract
- The pRb pathway plays a key role in controlling the G1/S transition in cell cycle progression. Aberrations of various components of the pRb pathway, such as retinoblastoma protein and its upstream actors including cyclin D1, cyclin dependence kinase-4 and p16/p15 cyclin dependent kinase inhibitors, have been reported in a variety of human tumors. Furthermore, the alterations of retinoblastoma protein and its upstream components often occur in a reciprocal manner. Previously, we have reported frequent inactivation of the Cdkn2a/Cdkn2b loci encoding p16/p15 cyclin dependent kinase inhibitors in a subset of 2',3'-dideoxycytidine- and 1,3-butadiene-induced mouse lymphomas (S.-M. Zhuang, A. Schippert, A. Haugen-Strano, R.W. Wiseman, P. Soderkvist, Inactivation of p16(INK4a)-a, p16(INK4a)-▀ and p15(INK4b) genes in 2',3'-dideoxycytidine- and 1,3-butadiene-induced lymphomas, Oncogene 16 (1998) 803-808), indicating the involvement of pRb pathway in lymphomagenesis. To investigate whether alteration of other components in pRb pathway is an alternative mechanism underlying the development of these chemically induced lymphomas, we have examined the genetic status of Rb1, Ccnd1 and Cdk4 genes that encode retinoblastoma protein, cyclin D1 and cyclin dependence kinase-4, respectively. Gross alterations of the Rb1, Ccnd1, and Cdk4 genes were not detected by Southern analysis in any of the tumors examined. In addition, single-strand conformation analysis failed to reveal point mutations in the Cdk4 amino terminal domain that is important for its association with Cdkn2a gene products. These results indicate that the mechanisms underlying the development of 2',3'-dideoxycytidine- and 1,3-butadiene-induced lymphomas involve inactivation of p16/p15 cyclin-dependent kinase inhibitors but not genomic alterations of the Rb1, Ccnd1 and Cdk4 genes. Copyright (C) 2000 Elsevier Science Ireland Ltd.
|
|
| 100. |
- Österström, Anna, et al.
(författare)
-
Expression of cytosolic and group X secretory phospholipase A2 genes in human colorectal adenocarcinomas
- 2002
-
Ingår i: Cancer Letters. - 0304-3835 .- 1872-7980. ; 182:2, s. 175-182
-
Tidskriftsartikel (refereegranskat)abstract
- Gene expression of cytosolic phospholipase A2 (cPLA2) and protein level of secretory PLA2 group X (sPLA2-X) are upregulated in human colorectal cancer and provide cyclooxygenase-2 (COX-2) with arachidonic acid, resulting in increased levels of PGE2. Mutated ras-genes are suggested to be involved in the regulatory pathway of cPLA2 in lung cancer cells. We analysed the gene expression of cPLA2 and sPLA2-X in 42 and 38 primary colorectal tumours, respectively, with and without K-ras mutations. We found an up-regulation of cPLA2 mRNA but the induction in tumour tissues does not correlate with Ras-gene mutations. Moreover, our results cannot consistently reflect an overexpression of sPLA2-X gene in colorectal cancer tissues.
|
|
