1
|
Shimazui T, Yoshikawa K, Ishitsuka R, Kojima T, Kandori S, Yoshino T, Miyazaki J, Uchida K, Nishiyama H. Systemic transduction of p16 INK4a antitumor peptide inhibits lung metastasis of the MBT-2 bladder tumor cell line in mice. Oncol Lett 2019; 17:1203-1210. [PMID: 30655885 DOI: 10.3892/ol.2018.9655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 07/27/2018] [Indexed: 11/05/2022] Open
Abstract
p16INK4a (p16) is a key molecule in bladder tumor (BT) development. We previously reported that a p16 antitumor peptide inhibited the growth of subcutaneous BT grafts in mice through restoration of p16 function using a Wr-T peptide transporter system. In the present study, the efficacy of mouse p16 peptide administration in a mouse lung metastasis model for BT and also the toxicity of peptides by cardiac peptide injection were evaluated. Mouse lung metastases were developed by tail vein injection of a p16-deficient MBT-2 cell line. Six-week-old C3H/He female mice were divided into three groups: A control group (n=12) receiving no treatment; a group treated once on the 3rd experimental day (n=12); and a group treated three times on the 3rd, 5th and 7th experimental days (n=10) with an injection of a mixture of 80 nmol mouse p16 peptide and 50 nmol Wr-T into the tail vein. At the 14th experimental day, the lung metastases were histologically evaluated. Lung metastases were observed in 100% (12/12), 41.7% (5/12) and 30% (3/10) of the aforementioned three groups, respectively. The number and area of metastatic lung tumors were significantly different between control and treatment groups (control vs. triple treatment group for the number and area, P=0.0029 and P=0.0296, respectively). Immunohistochemistry demonstrated that phosphorylated retinoblastoma (Rb) protein was decreased in lung tumors of the treatment groups, compared with the control group. The toxicity of p16 peptide transduction was evaluated by using low-dose treatment (three dosages) and high-dose treatment (two dosages) on three male and three female C3H/He mice in early and late experimental phases. In low and high dose groups, no notable change was determined in body weight or blood analyses in early or late phases following mouse p16 peptide administration. In addition, no notable change was observed histologically in bone marrow of treatment groups. To conclude, systemic p16 peptide administration decreased lung tumor development in a mouse metastatic BT model without severe adverse events, as assessed by blood analyses and histological evaluation.
Collapse
Affiliation(s)
- Toru Shimazui
- Department of Urology, Ibaraki Clinical Education and Training Center, Faculty of Medicine, University of Tsukuba, Kasama, Ibaraki 309-1793, Japan.,Department of Urology, Ibaraki Prefectural Central Hospital, Kasama, Ibaraki 309-1793, Japan
| | - Kazuhiro Yoshikawa
- Division of Research Creation and Biobank, Research Creation Support Center, Aichi Medical University, Nagakute, Aichi 480-1195, Japan
| | - Ryutaro Ishitsuka
- Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Takahiro Kojima
- Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Shuya Kandori
- Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Takayuki Yoshino
- Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Jun Miyazaki
- Department of Urology, School of Medicine, International University of Health and Welfare, Ichikawa, Chiba 272-0827, Japan
| | - Kazuhiko Uchida
- Department of Molecular Biological Oncology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroyuki Nishiyama
- Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| |
Collapse
|
2
|
Arantes-Rodrigues R, Pinto-Leite R, da Costa RG, Colaço A, Lopes C, Oliveira P. Cytogenetic characterization of an N-butyl-N-(4-hydroxybutyl) nitrosamine-induced mouse papillary urothelial carcinoma. Tumour Biol 2013; 34:2691-6. [DOI: 10.1007/s13277-013-0820-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022] Open
|
3
|
Shimazui T, Yoshikawa K, Miyazaki J, Kojima T, Inai H, Ando S, Uemura H, Uchida K, Nishiyama H. Systemic transduction of p16INK4A antitumor peptide inhibits the growth of MBT-2 mouse bladder tumor cell line grafts. Int J Oncol 2012; 42:543-8. [PMID: 23292502 DOI: 10.3892/ijo.2012.1752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/23/2012] [Indexed: 11/05/2022] Open
Abstract
p16(INK4a) (p16), a key molecule in bladder tumor development, inhibits the activities of cyclin-dependent kinases (CDKs) and maintains the retinoblastoma protein (pRb) in its active hypophosphorylated state. Following the finding that the p16 antitumor peptide dramatically inhibits the growth of aggressive leukemia/lymphoma through the restoration of p16 function using the Wr-T peptide transporter system, in this study, we developed a systemic therapy using mouse‑p16 peptide (m‑p16) in subcutaneous p16‑null mouse bladder tumors. In vitro analysis showed that the growth of p16‑null bladder tumor cells and the hyperphosphorylation of their pRbs were inhibited by p16 transduction in a concentration‑dependent manner. In an animal model, p16‑null MBT‑2 cells were injected subcutaneously into KSN/SKC nude mice. The systemic delivery of the m‑p16 peptide using Wr‑T by cardiac injection significantly inhibited the growth of solid MBT‑2 tumors compared with the control phosphate‑buffered saline (PBS) injection. Histological examination by TUNEL staining revealed that apoptosis was increased and pRb phosphorylation was inhibited. Thus, the systemic peptide delivery of p16 restores the hypophosphorylation of pRb and may be a useful tool for the treatment of bladder tumors.
Collapse
Affiliation(s)
- Toru Shimazui
- Department of Urology, Ibaraki Clinical Education and Training Center, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Abstract
Experimental animal models are extremely valuable for the study of human diseases, especially those with underlying genetic components. The exploitation of various animal models, from fruitflies to mice, has led to major advances in our understanding of the etiologies of many diseases, including cancer. Cutaneous malignant melanoma is a form of cancer for which both environmental insult (i.e., UV) and hereditary predisposition are major causative factors. Fish melanoma models have been used in studies of both spontaneous and induced melanoma formation. Genetic hybrids between platyfish and swordtails, different species of the genus Xiphophorus, have been studied since the 1920s to identify genetic determinants of pigmentation and melanoma formation. Recently, transgenesis has been used to develop zebrafish and medaka models for melanoma research. This review will provide a historical perspective on the use of fish models in melanoma research, and an updated summary of current and prospective studies using these unique experimental systems.
Collapse
Affiliation(s)
- E Elizabeth Patton
- Institute for Genetics and Molecular Medicine, MRC Human Genetics Unit and Division of Cancer Research, The University of Edinburgh, Edinburgh, UK.
| | | | | |
Collapse
|
5
|
Butler AP, Trono D, Coletta LD, Beard R, Fraijo R, Kazianis S, Nairn RS. Regulation of CDKN2A/B and Retinoblastoma genes in Xiphophorus melanoma. Comp Biochem Physiol C Toxicol Pharmacol 2007; 145:145-55. [PMID: 17011832 DOI: 10.1016/j.cbpc.2006.07.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 07/12/2006] [Accepted: 07/31/2006] [Indexed: 02/02/2023]
Abstract
Xiphophorus interspecies hybrids provide several well-characterized genetic models of melanoma susceptibility. The Xiphophorus CDKN2A/B gene, homologous to mammalian CDKN2A/B cyclin-dependent kinase inhibitors (p16 and p15), is a candidate tumor susceptibility gene in these models. Using real-time PCR and Western blot analysis, we analyzed expression of CDKN2A/B in spontaneous and UV-induced primary melanomas from individual backcross hybrid fish. We found that CDKN2A/B mRNA is highly expressed in melanomas (18-fold), relative to other fish tissues. Expression is also elevated, to a lesser extent (9.5-fold), in melanized skin from tumor-bearing fish. However, quantitative levels of CDKN2A/B mRNA in tumors varied considerably and positively correlated with expression of the Xmrk oncogene, suggesting possible functional interaction between Xmrk and CDKN2A/B expression. As a homolog corresponding to members of the mammalian CDKN2 family which regulate cell cycle progression at the G1 checkpoint, the CDKN2A/B p13 protein is a putative regulator of the G1 checkpoint apparatus in Xiphophorus. Since CDKN2A is often observed to be inversely regulated compared to RB in some human tumors, and is capable of transcriptionally regulating RB in human ovarian tumors, we cloned the Xiphophorus maculatus RB cDNA and analyzed RB expression by real-time PCR and Western blot analysis in the fish melanomas. These experiments were designed to ascertain whether CDKN2A/B and RB expression were inversely correlated. Our results indicate that RB mRNA was consistently expressed at only a 2-fold higher level in both tumors and melanized skin than in muscle. Qualitatively similar results were obtained for protein expression. These results collectively suggest that (i) Xmrk and CDKN2A/B may be co-regulated at the transcriptional level, and (ii) there is little, if any, alteration of RB expression in Xiphophorus melanomas.
Collapse
Affiliation(s)
- Andrew P Butler
- Virginia Harris Cockrell Cancer Research Center, Department of Carcinogenesis, Science Park-Research Division, University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA.
| | | | | | | | | | | | | |
Collapse
|
6
|
Butler AP, Trono D, Beard R, Fraijo R, Nairn RS. Melanoma susceptibility and cell cycle genes inXiphophorus hybrids. Mol Carcinog 2007; 46:685-91. [PMID: 17477382 DOI: 10.1002/mc.20343] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Xiphophorus interspecies hybrids provide genetically defined models of both spontaneous and inducible melanomagenesis. In both models, backcrossing F(1) hybrids of different strains of X. maculatus and X. helleri to a X. helleri parental fish results in segregation of melanoma susceptibility, fitting a Mendelian two-gene inheritance model. The sex-linked Xmrk oncogene is required for melanoma development in both crosses. The Xiphophorus CDKN2A/B gene, which is homologous to mammalian CDKN2A/B cyclin-dependent kinase inhibitors (p16 and p15), is a candidate melanoma susceptibility gene. In this model, tumor susceptibility segregates with homozgyosity for CDKN2A/B from the recurrent X. helleri parent in backcross hybrids. We found that both CDKN2A/B mRNA and protein are highly overexpressed in melanoma. Because the p13 protein product of CDKN2A/B is a putative regulator of the G1 checkpoint, we investigated expression of other components of Xiphophorus G1 checkpoint control. By real-time PCR analysis, retinoblastoma gene (RB) is consistently expressed twofold higher in both tumors and melanized skin than in normal tissue, indicating that RB is not downregulated by the overexpression of CDKN2A/B in Xiphophorus melanoma. We also found a significant correlation between the quantitative level of CDKN2A/B and Xmrk RNA in tumors, suggesting a functional relationship between Xmrk and CDKN2A/B expression. Although X. helleri CDKN2A/B protein contains a non-conservative substitution, the biochemical function appears to show little overt defect. These studies indicate that in Xiphophorus melanoma, CDKN2A/B is functionally insufficient to mediate cell-cycle arrest in the presence of Xmrk.
Collapse
Affiliation(s)
- Andrew P Butler
- Department of Carcinogenesis, University of Texas, M. D. Anderson Cancer Center, Science Park, Research Division, Smithville, Texas 78957, USA
| | | | | | | | | |
Collapse
|
7
|
Obata M, Imamura E, Yoshida Y, Goto J, Kishibe K, Yasuda A, Ogawa K. Resistance of primary cultured mouse hepatic tumor cells to cellular senescence despite expression of p16(Ink4a), p19(Arf), p53, and p21(Waf1/Cip1). Mol Carcinog 2001; 32:9-18. [PMID: 11568971 DOI: 10.1002/mc.1059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Primary cultured mouse hepatic cells become senescent within a short period, although rare cells form colonies from which continuously proliferating cell lines can be established. In contrast, hepatic tumor (HT) cells show little senescence and higher colony-forming capacity. To assess this difference, we investigated p16(Ink4a)/p19(Arf)/p53/p21(Waf1/Cip1) expression in primary normal and HT cells, together with cell lines established from both. In primary normal cells, p16(Ink4a)/p19(Arf) were expressed only in association with senescence and disappeared at later stages of colony formation. In contrast, primary HT cells showed sustained p16(Ink4a)/p19(Arf) expression from the beginning. No p16(Ink4a)/p19(Arf) alterations, such as deletion, mutations, or hypermethylation, were detected in the primary HT cells, although most cell lines derived from either normal or HT cell colonies lost p16(Ink4a) or p19(Arf) expression owing to hypermethylation or homozygous deletion of p16(Ink4a)/p19(Arf). On the other hand, primary normal and HT cells and most cell lines showed constitutively elevated expression of p53/p21(Waf1/Cip1), with a further increment after ultraviolet ir-radiation, indicating a functionally normal p53 pathway. These results indicate that primary HT cells are resistant to senescence despite retaining p16(Ink4a)/p19(Arf)/p53/p21(Waf1/Cip1) expression and that loss of p16(Ink4a)/p19(Arf) function is associated only with establishment of the cell lines.
Collapse
Affiliation(s)
- M Obata
- Department of Pathology, Asahikawa Medical College, Asahikawa, Japan
| | | | | | | | | | | | | |
Collapse
|
8
|
Wang QS, Papanikolaou A, Nambiar PR, Rosenberg DW. Differential expression of p16(INK4a) in azoxymethane-induced mouse colon tumorigenesis. Mol Carcinog 2000; 28:139-47. [PMID: 10942530 DOI: 10.1002/1098-2744(200007)28:3<139::aid-mc2>3.0.co;2-v] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alterations in the p16(INK4a) gene have been implicated in the pathogenesis of different human cancers and animal tumors. We postulated that alterations in the p16(INK4a) gene may also be involved in mouse colon tumorigenesis induced by the chemical carcinogen azoxymethane (AOM). In the present study, p16(INK4a) deletion status and its expression were examined in an AOM-induced mouse colon tumor model. Polymerase chain reaction-based deletion analysis of p16(INK4a) exon 2 showed no deletions in the colon tumors. The expression and localization of p16(INK4a) and its gene product were examined by reverse transcription-polymerase chain reaction and immunohistochemical analyses, respectively. The p16(INK4a) mRNA levels were low, and in some cases undetectable, in control colon tissue. However, colon tumors exhibited an eightfold increase in p16(INK4a) mRNA level when compared with control colon tissue (P < 0.01). Whereas control colon epithelium was uniformly negative for p16(INK4a) immunoreactivity, p16(INK4a)-immunoreactive cells were markedly increased in preneoplastic lesions and adenomas isolated from AOM-treated mice. To further examine the p16(INK4a) regulatory pathway, the retinoblastoma tumor-suppressor protein (Rb) was also examined immunohistochemically in these tissues. A heterogeneous Rb immunostaining was observed in preneoplastic lesions and adenomas. Immunohistochemical analysis also showed a reciprocal relationship between p16(INK4a) and Rb protein expression. These findings suggest that alterations in the p16(INK4a)/Rb pathway may play an important role in AOM-induced mouse colon tumorigenesis. Mol. Carcinog. 28:139-147, 2000.
Collapse
Affiliation(s)
- Q S Wang
- Toxicology Program, Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269, USA
| | | | | | | |
Collapse
|
9
|
Kazianis S, Coletta LD, Morizot DC, Johnston DA, Osterndorff EA, Nairn RS. Overexpression of a fish CDKN2 gene in a hereditary melanoma model. Carcinogenesis 2000; 21:599-605. [PMID: 10753192 DOI: 10.1093/carcin/21.4.599] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The fish genus Xiphophorus provides a vertebrate model useful in etiological studies of cancer. Hybrid fish can spontaneously develop melanomas deriving from the inheritance of melanistic pigment patterns and the simultaneous absence of proper genetic regulation. A cyclin-dependent kinase inhibitor gene, termed CDKN2X, was mapped to a genomic region that is implicated in fish melanoma tumor suppression. The related human tumor suppressor locus CDKN2A (P16, INK4A, MTS1) is deleted, mutated or transcriptionally repressed through methylation of cytosine bases within the 5' CpG island in a variety of neoplasms, including melanoma. The fish CDKN2X locus harbors a CpG island within its promoter and first exon, analogous in location to CpG islands in human CDKN2A and CDKN2B loci. The methylation state of individual CpG dinucleotides was investigated in genomic DNA derived from control tissues and melanomas within the CDKN2X 5' CpG island. The studied genomic area was found to be virtually unmethylated in all tested tissues including melanomas. In addition, RNA expression studies of the fish CDKN2X locus revealed that it is significantly overexpressed in melanoma, in contrast to what has been reported for the human CDKN2A locus in melanoma. Such overexpression may be a consequence of the pronounced upregulation of the Xmrk-2 receptor tyrosine kinase oncogene reported in several Xiphophorus melanoma models.
Collapse
Affiliation(s)
- S Kazianis
- Department of Carcinogenesis, Science Park-Research Division, MD Anderson Cancer Center, University of Texas, PO Box 389, Smithville, TX 78957, USA.
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
The tumor suppressor p16INK4a is a potent mediator of cell cycle arrest in transient expression studies, is induced in senescing cells, and can impose morphological features of senescence. Nonetheless, it is unclear whether p16INK4a can block cell proliferation irreversibly. We explored this issue using osteogenic sarcoma cell clones with inducible p16INK4a expression. Induction of p16INK4a for 1 day arrested most cells in G1 phase. If the induction was then interrupted, p16INK4a levels returned to baseline and robust growth resumed within 3-5 days. When p16INK4a was induced for 6 days DNA synthesis remained strongly inhibited and the cells acquired morphological features of senescence. Moreover, if p16INK4a induction was interrupted at this point and the cells were followed for 12 more days, most cells retained these morphologic features and either failed to divide or died. This occurred despite the prompt return of p16INK4a expression and retinoblastoma protein phosphorylation toward baseline levels. In fact, some senescing cells appeared to enter S phase. These results demonstrate that a sustained period of p16INK4a expression is sufficient in this setting to impose a durable block to cell proliferation and that this state becomes independent of p16INK4a expression, hypophosphorylation of pRB, or a strict G1 arrest.
Collapse
Affiliation(s)
- C Y Dai
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104-6144, USA
| | | |
Collapse
|
11
|
Claeskens A, Ongenae N, Neefs JM, Cheyns P, Kaijen P, Cools M, Kutoh E. Hevin is down-regulated in many cancers and is a negative regulator of cell growth and proliferation. Br J Cancer 2000; 82:1123-30. [PMID: 10735494 PMCID: PMC2363342 DOI: 10.1054/bjoc.1999.1051] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have cloned a human Hevin cDNA from omental adipose tissue of different patients by reverse transcription polymerase chain reaction and shown a sequence variation due to a possible polymorphism at amino acid position 161 (E/G). Hevin protein expressed in vitro showed molecular weights of approximately 75 kDa and 150 kDa, suggesting that Hevin may form a homodimer in vitro. Using Northern blots and a human expressed sequence tAg database analysis, Hevin was shown to be widely expressed in human normal or non-neoplastic diseased tissues with various levels. In contrast to this, its expression was strongly down-regulated in most neoplastic cells or tissues tested. However, neither the mechanism nor the physiological meaning of this down-regulation is known. As an initial step towards investigating the functional role of Hevin in cell growth and differentiation, we transiently or stably expressed this gene in cancer cells (HeLa 3S) that are devoid of endogenous Hevin and measured DNA synthesis (cell proliferation) by 5-bromo-2'-deoxyuridine incorporation. Hevin was shown to be a negative regulator of cell proliferation. Furthermore, we have shown that Hevin can inhibit progression of cells from G1 to S phase or prolong G1 phase. This is the first report which describes the function of Hevin in cell growth and proliferation. Through database analysis, Hevin was found to be located on chromosome 4 which contains loss of heterozygosity of many tumour suppressor genes. Taken together, these results suggest that Hevin may be a candidate for a tumour suppressor gene and a potential target for cancer diagnosis/therapy.
Collapse
Affiliation(s)
- A Claeskens
- Department of Biochemistry, Janssen Research Foundation, Beerse, Belgium
| | | | | | | | | | | | | |
Collapse
|
12
|
In situ PCR and immunohistochemical studies on p16 gene in pituitary adenomas. Chin J Cancer Res 2000. [DOI: 10.1007/bf02983186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
13
|
Park YG, Song CW, Mori N, Sugimoto K, Hong DP, Okumoto M. Analysis of highly frequent allelic loss region on distal chromosome 12 in murine radiation-induced lymphomas. Cancer Lett 2000; 148:95-103. [PMID: 10680598 DOI: 10.1016/s0304-3835(99)00321-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent genetic studies of tumorigenesis have strongly suggested an existence of tumor suppressor gene(s) on murine chromosome 12 and human chromosome 14q32. We previously described that putative tumor suppressor gene(s) might reside between D12Mit53 and D12Mit233. We analyzed three genes, Tcl1, Yy1 and Tnfalphaip2, which had been mapped around the region, as the candidates in radiation lymphomagenesis of (BALB/c x MSM/Ms)F1 hybrid mice. The locus order and distances of the three genes and microsatellite loci were estimated as follows: [centromere] - Tcl1-(> or =0.085 cM)-D12Mit50-(0.085 cM)D12Mit132-(1.96 cM)D12Mit122-(0.085 cM)D12Mit53-(1.37 cM)-[D12Mit233,D12Mit279,Yy1]-(0.085 cM)-D12Mit181-(> or =0.17 cM)-Tnfalphaip2 - [telomere]. Allele losses at Tcl1, Yy1 genes and D12Mit233 were observed in 94(45%), 143(68%) and 147(70%) of 210 lymphomas, respectively. In semi-quantitative analysis of Yy1 mRNA levels by RT-PCR, kinetics of the yield of the Yy1-cDNA-specific PCR products showed almost the same profiles among thymic lymphomas with allelic loss at Yy1, lymphomas with both alleles retained and normal thymus. These results suggest that Tcl1, Yy1 and Tnfalphaip2 genes are not predominantly involved in radiation lymphomagenesis of mice. In further analysis of the common allelic loss region, we found new loci, Y152pR1 and Y184pR2, from YACs which located in the hot region between D12Mit53 and D12Mit233, and the highest frequency of allelic loss (71%) was observed at the Y184pR2 locus. The LOH patterns of individual lymphomas suggest that putative tumor suppressor gene(s) lies between Y152pR1 and Y184pR2.
Collapse
Affiliation(s)
- Y G Park
- Graduate School of Agriculture, Osaka Prefecture University, Sakai, Japan
| | | | | | | | | | | |
Collapse
|
14
|
Kazianis S, Morizot DC, Coletta LD, Johnston DA, Woolcock B, Vielkind JR, Nairn RS. Comparative structure and characterization of a CDKN2 gene in a Xiphophorus fish melanoma model. Oncogene 1999; 18:5088-99. [PMID: 10490845 DOI: 10.1038/sj.onc.1202884] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We have cloned, sequenced, and characterized the RNA expression properties of a fish CDKN2 gene from Xiphophorus helleri and X. maculatus. This gene, termed CDKN2X, shows a high degree of amino acid sequence similarity to members of the mammalian CDKN2 gene family, which includes the tumor suppressor loci CDKN2A (P16) and CDKN2B (P15). Comparative sequence analysis suggests that fish CDKN2X is similarly related to all four mammalian gene family members, and may represent a descendant of an ancestral prototypic CDKN2 gene. CDKN2X was mapped to a region on autosomal Xiphophorus linkage group V (LG V) known to contain the DIFF gene that acts as a tumor suppressor of melanoma formation in X. helleri/X. maculatus backcross hybrids. Thus, CDKN2X may be a candidate for the tumor suppressor DIFF gene. Here we have sequenced CDKN2X in both Xiphophorus species and have characterized its expression in normal and melanotic tissues within control and backcross hybrid fish. A simultaneous expressional analysis of the Xmrk-2 tyrosine kinase receptor gene, which is strongly implicated in melanomagenesis in this system, was also performed. RT - PCR analyses revealed that both genes were highly expressed in melanomas. For CDKN2X, this result contrasts numerous findings in human tumors including human melanoma in which either CDKN2A (P16) deactivation or LOH was observed.
Collapse
Affiliation(s)
- S Kazianis
- Department of Carcinogenesis, Science Park-Research Division, MD Anderson Cancer Center, University of Texas, Smithville, Texas, TX 78957-0389, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Mitra J, Dai CY, Somasundaram K, El-Deiry WS, Satyamoorthy K, Herlyn M, Enders GH. Induction of p21(WAF1/CIP1) and inhibition of Cdk2 mediated by the tumor suppressor p16(INK4a). Mol Cell Biol 1999; 19:3916-28. [PMID: 10207115 PMCID: PMC84249 DOI: 10.1128/mcb.19.5.3916] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/1998] [Accepted: 02/22/1999] [Indexed: 11/20/2022] Open
Abstract
The tumor suppressor p16(INK4a) inhibits cyclin-dependent kinases 4 and 6. This activates the retinoblastoma protein (pRB) and, through incompletely understood events, arrests the cell division cycle. To permit biochemical analysis of the arrest, we generated U2-OS osteogenic sarcoma cell clones in which p16 transcription could be induced. In these clones, binding of p16 to cdk4 and cdk6 abrogated binding of cyclin D1, p27(KIP1), and p21(WAF1/CIP1). Concomitantly, the total cellular level of p21 increased severalfold via a posttranscriptional mechanism. Most cyclin E-cdk2 complexes associated with p21 and became inactive, expression of cyclin A was curtailed, and DNA synthesis was strongly inhibited. Induction of p21 alone, in a sibling clone, to the level observed during p16 induction substantially reproduced these effects. Overexpression of either cyclin E or A prevented p16 from mediating arrest. We then extended these studies to HCT 116 colorectal carcinoma cells and a p21-null clone derived by homologous recombination. In the parental cells, p16 expression also augmented total cellular and cdk2-bound p21. Moreover, p16 strongly inhibited DNA synthesis in the parental cells but not in the p21-null derivative. These findings indicate that p21-mediated inhibition of cdk2 contributes to the cell cycle arrest imposed by p16 and is a potential point of cooperation between the p16/pRB and p14(ARF)/p53 tumor suppressor pathways.
Collapse
Affiliation(s)
- J Mitra
- Departments of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | |
Collapse
|