Aurora-A and Cyclin D1 polymorphisms and the age of onset of colorectal cancer

in hereditary nonpolyposis colorectal cancer

Bente A. Talseth1,2, Katie A. Ashton1,2, Cliff Meldrum3, Janina Suchy4, Grzegorz Kurzawski4, Jan Lubinski4

and Rodney J. Scott1,2,3*

1Discipline of Medical Genetics, Faculty of Health, University of Newcastle, Newcastle, NSW, Australia2Hunter Medical Research Institute, NSW, Australia3Division of Genetics, Hunter Area Pathology Service, John Hunter Hospital, Newcastle, NSW, Australia4International Hereditary Cancer Center, Department of Genetics and Pathology, Szczecin, Poland

Polymorphisms in the 2 cell-cycle control genes Aurora A andCyclin D1 have previously been associated with changes in the ageof onset of colorectal cancer in persons harboring germline muta-tions in DNA mismatch repair genes associated with hereditarynonpolyposis colorectal cancer (HNPCC). In this report, we havegenotyped 312 individuals, who all harbored confirmed causativemutations in either hMSH2 or hMLH1, for 2 polymorphisms, onein Aurora A (T91A) and the other in Cyclin D1 (G870A). Theresults reveal that the previous association with the Aurora Apolymorphism could not be confirmed in our larger group ofHNPCC patients. The Cyclin D1 polymorphism, however, wasassociated with a significant difference in the age of disease onseton patients harboring hMSH2 mutations, which was not observedin hMLH1 mutation carriers. A combined analysis of the Aurora Aand Cyclin D1 polymorphisms did not reveal any obvious associa-tion. In conclusion, it appears that the polymorphic variant ofAurora A does not appear to be associated with variation in color-ectal cancer risk in HNPCC, whereas there is a more complexrelationship between the Cyclin D1 polymorphism and disease riskin HNPCC.' 2007 Wiley-Liss, Inc.

Key words: Aurora A; Cyclin D1; HNPCC; colorectal cancer; diseaserisk, polymorphisms

Hereditary nonpolyposis colorectal cancer (HNPCC) is an auto-somal dominantly inherited predisposition to develop early onsetepithelial cancers, especially colorectal cancer and endometrialcancer, as a result of germline mutations occurring in DNA mis-match repair (MMR) genes.1–6 There is, however, considerablevariation in disease expression (age of onset and tumor site) in thisdisorder which cannot be entirely explained by the type and posi-tion of the mutation in the respective genes.7 Several reports haveshown that genetic polymorphisms may be contributing factors todisease in HNPCC.8–11

Two single nucleotide polymorphisms (SNPs) in genes involvedin the cell cycle, Aurora-A and Cyclin D1, have been associatedwith the age of onset of colorectal cancer (CRC) in HNPCC pa-tients.12,13 HNPCC patients homozygous for the wild-type allele(TT) in the T91A SNP (F31I) in Aurora-A developed CRC �7years earlier than patients carrying the variant allele.12 This asso-ciation was increased after stratifying for the G870A SNP atcodon 242 in Cyclin D1, which had previously been associatedwith an earlier age of disease diagnosis by an average of 11 yearscompared to patients homozygous for the wild-type allele.13

Aurora-A is involved in the normal cell cycle but is overex-pressed in a variety of malignancies.14–22 Aurora-A positively reg-ulates the G2-to-M phase of the cell cycle, and the activation ofAurora-A in late G2 is inhibited by DNA damage.15 DNA repairand cell-cycle control might be linked together as it has been sug-gested that MMR genes are necessary to activate the G2-M check-point in the presence of certain types of DNA damage.23

Cyclin D1 has an important role in the G1-to-S phase in the cellcycle.24 The G870A SNP in Cyclin D1 enhances alternate splicingof the gene, and the protein encoded by the alternate transcriptmay have a longer half life.25 Several studies have suggested thatthere is a relationship between the G870A SNP in Cyclin D1 and

the age of disease onset in HNPCC. The relationship betweenCyclin D1 and disease expression in HNPCC appears to be com-plex as one study shows an association between the polymorphismand age of disease onset,13 whereas a second study from Finlandfailed to show a similar relationship, but did observe a decreasedage of disease onset for homozygote wild-type and mutant allelescompared to heterozygotes,26 suggestive of heterosis. The majordifference between the 2 studies was the predominance of hMSH2mutation carriers in one population compared to hMLH1 carriersin the other.

One of the major shortcomings with all of the previous reportson the relationship between the age of disease onset and respectivegenotype in Aurora-A and Cyclin D1 was the number of individu-als used in each study, all of which were relatively small.12,13,26

To understand the biological basis of the relationship betweendisease phenotype and polymorphisms in Aurora-A and CyclinD1, additional studies on larger groups of HNPCC patients arerequired.

In this report, we have genotyped 312 HNPCC individuals forthe G>A SNP at codon 242 in Cyclin D1 and the 91T>A SNP(F31I) in Aurora-A, all with confirmed causative germline muta-tions in either hMSH2 or hMLH1.

Material and methods

Participants

All the participants selected for this study had previously beendiagnosed with HNPCC, and the selection criteria were based onthe molecular diagnosis of HNPCC. The 312 participants harborgermline mutations in either hMLH1 or hMSH2. There were 177cases with germline hMLH1 mutations and 135 with hMSH2mutations, of which there were 255 (82%) nonsense insertion,deletion or splice mutations (leading to a truncated protein) and 57(18%) missense mutations described as pathogenic in the Interna-tional Society for Gastrointestinal Hereditary Tumours (InSiGHT)mutation database. Fifty three 53 (17%) of the missense mutationswere in hMLH1 mutation carriers, while 4 (1%) were in hMSH2mutation carriers. Local ethics committees in Poland and Australiaapproved the study.

Of the 312 HNPCC participants, 220 have been described previ-ously.27 Ninety-two new samples from Poland have since beenadded to the study. The new samples include 33 CRC probands,6 uterine cancer probands and 53 relatives (57%). Briefly, thesample population consists of 86 participants from Australia and226 participants from Poland, 22 (26%) of the Australian and131 (58%) of the Polish participants were relatives of probands.Of the 312 participants, 157 had been diagnosed with colorectal

*Correspondence to: Hunter Area Pathology Service, John HunterHospital, Lookout Rd., New Lambton Heights, 2305 NSW, Australia.Fax:161-0-2-4921-4253. E-mail: rodney.scott@newcastle.edu.auReceived 20 June 2007; Accepted after revision 8 August 2007DOI 10.1002/ijc.23177Published online 20 November 2007 inWiley InterScience (www.interscience.

wiley.com).

Int. J. Cancer: 122, 1273–1277 (2008)' 2007 Wiley-Liss, Inc.

Publication of the International Union Against Cancer

cancer (CRC). The distribution of second cancers was similarbetween hMLH1 and hMSH2 mutation carriers. The 6 probandsdiagnosed with endometrial cancer were considered as controlssince we were specifically focusing on colorectal cancer and noton any other malignancy common in HNPCC.

The median age of participants diagnosed with CRC and unaf-fected MMR gene mutation carriers were 43 years and 39.5 years,respectively. The median age did not differ between hMLH1 andhMSH2 mutation carriers; 43 years for both groups of participantsdiagnosed with CRC and 40.5 years for hMLH1 and 39 years forhMSH2 carriers for unaffected MMR gene mutation carriers.

SNP genotyping

Genotyping was performed on an ABI PRISM1

7500 Real-Time PCR System (PE Applied Biosystems, Foster City, CA),using primers and probes from Assay-by-Demand (Applied Bio-systems) for Aurora-A (rs2273535, assay ID: C__25623289_10)and Cyclin D1 (rs603965, assay ID: C_744725_1). The assay wasperformed under universal conditions previously described.27

Statistical analysis

Pearson’s v2 was used to evaluate the deviation from theexpected Hardy-Weinberg equilibrium and for comparison of thedistributions of the genotypes, while odds ratio (OR) and 95%confidence intervals (CI) were calculated using a 2 3 2 table.Kaplan-Meier survival analysis was used to plot the proportion ofthe population that was cancer free versus the subject’s age ofdiagnosis of colorectal cancer (CRC). By comparing the Kaplan-Meier survival curves plotted by genotype, we tested the associa-tion between age of diagnosis of CRC and genotypes. The Wilcox-on’s test, which emphasizes observations from early diagnosis,log-rank test, which gives more weight to later ages and Tarone-Ware test, which is an intermediate of the 2 other tests, were usedto examine the homogeneity of the survival curves. If the resultswere insignificant, the p value of the log-rank test was reported.The significance levels of all tests were set at p < 0.05. All statisti-cal analyses were performed with Intercooled Stata 8.0 (Stata

Corp., College Station, TX) and GraphPad Instat version 3.06(GraphPad Software, San Diego, CA).

Results

The genotypes and allele frequency distribution for Aurora-A(rs2273535) and Cyclin D1 (rs603965) are presented in Table I.

Genotype frequency distribution

Ten samples (2 from the nonaffected hMLH1 group, 4 from thenonaffected hMSH2 group and 2 each from the affected hMSH2and hMLH1 groups) consistently failed to amplify for theAurora-A SNP and were consequently not included in the statisti-cal analysis.

The frequencies of both SNPs were in Hardy-Weinberg equilib-rium. The allele frequencies observed in this study were not differ-ent from those reported for Caucasian subjects (http://snp500can-cer.nci.nih.gov), p 5 0.90 for Aurora-A and p 5 0.95 for CyclinD1. The genotype frequencies were not significantly differentbetween Australian and Polish samples (data not shown). Whencomparing genotype frequencies for the Aurora-A and Cyclin D1SNPs between unaffected MMR gene mutation carriers (CRC–)and the colorectal cancer MMR gene mutation carriers (CRC1),no significant differences were observed. Similarly, no significantdifferences were observed between male or female participants,affected or not.

A significant difference was observed for the Cyclin D1 SNPfrequency between hMLH1 and hMSH2 mutation carriers whencomparing individuals with the wild-type genotype (GG) to indi-viduals with any variant allele (GA and AA combined), p 5 0.03.

Kaplan-Meier survival analysis

No significant difference between the age of diagnosis of CRCand genotype was observed for either of the 2 SNPs in this studywhen assessing the subject group, whether comparing the 3 geno-types or combining heterozygotes and variant genotype (see Fig. 1).

TABLE I – STUDY DEMOGRAPHICS OF THE AURORA-A AND CYCLIN D1 SNPS IN HNPCC PATIENTS ACCORDING TO DISEASE EXPRESSION(AFFECTED WITH CRC (CRC1) AND UNAFFECTED MMR GENE MUTATION CARRIERS (CRC2))

Aurora-A rs2273535 TT (%) TA (%) AA (%) Any A (%) p value1

Subject group (n5 302) 175 (58) 113 (37) 14 (5)Allele frequency 0.767 0.233

CRC1 (n5 153) 91 (59) 53 (35) 9 (6) 62 (41) p5 0.471

CRC2 (n5 147) 84 (57) 58 (39) 5 (3) 63 (42)2OR5 1.10 95% CI 5 0.70–1.74 p5 0.76

hMLH1 (n5 173) 96 (55) 68 (39) 9 (5) 77 (44) p5 0.561

hMSH2 (n5 129) 79 (61) 45 (35) 5 (4) 50 (39)2OR5 0.79 95% CI 5 0.50–1.26 p5 0.38

Female (n5 177) 100 (56) 70 (40) 7 (4) 77 (44) p5 0.571

Male (n5 122) 73 (60) 42 (34) 7 (6) 49 (40)2OR5 0.87 95% CI 5 0.55–1.39 p5 0.65

Cyclin D1 rs603965 GG (%) GA (%) AA (%) Any A (%) p value1

Subject group (n5 312) 76 (24) 160 (51) 76 (24)Allele frequency 0.500 0.500

CRC1 (n5 157) 34 (22) 78 (50) 45 (29) 123 (79) p5 0.181

CRC2 (n5 153) 42 (27) 80 (52) 31 (20) 111 (72)2OR 5 0.73 95% CI 5 0.43–1.23 p5 0.29

hMLH1 (n5 177) 52 (29) 85 (48) 40 (23) 125 (71) p5 0.061

hMSH2 (n5 135) 24 (18) 75 (56) 36 (27) 111 (83)2OR 5 1.92 95% CI 5 1.11–3.33 p5 0.03

Female (n5 186) 48 (26) 88 (47) 50 (27) 138 (74) p5 0.191

Male (n5 123) 27 (22) 71 (58) 25 (20) 96 (78)2OR 5 1.24 95% CI 5 0.72–2.12 p5 0.52

CRC1 5 colorectal cancer patients, CRC2 5 unaffected MMR gene mutation.1Comparison of genotype frequencies using Pearson’s w2.–2OR is the relative risk for patients with ‘‘Any A’’ genotype relative to those with

the wildtype genotype (TT for Aurora-A and GG for Cyclin D1). CI 5 confidence intervals.

1274 TALSETH ET AL.

The median age of diagnosis of CRC, or the age at which 50% ofthe population is cancer-free, was not significantly differentbetween the genotypes for Aurora-A or Cyclin D1. Similarly,when dividing the subject group by gender, no difference wasobserved between age of diagnosis of CRC and genotype betweenfemales and males.

For Cyclin D1, there is a significant difference between age ofdiagnosis of CRC and genotype in the hMSH2 mutation carriers,but not hMLH1 mutation carriers (see Fig. 2). The hMSH2 muta-tion carriers harboring the wild-type (GG) genotype developedCRC on average 30 years later than individuals with the variantgenotype (AA) and 24 years later than individuals with the hetero-zygote genotype (GA), p 5 0.03 (log-rank test), p 5 0.03

(Wilcoxon test) and p 5 0.02 (Tarone-Ware test). When combin-ing the heterozygote and variant genotype (GA 1 AA), there wasa difference of 26 years, p 5 0.01 (log-rank test), p 5 0.04 (Wil-coxon test) and p 5 0.02 (Tarone-Ware test); see Table II.

Discussion

Since the identification of the genetic basis of HNPCC manystudies have been undertaken to identify modifier genes that mayexplain, at least in part, the variation in disease expression in thiscancer syndrome. Functional studies of the 2 SNPs investigated inthis study indicate that the variant allele of Cyclin D1 (A)increases alternate splicing25 of the gene, which has been associ-ated with nonsmall cell lung cancer,25 squamous cell carcinoma ofthe head and neck28 and the prompt for this current study, the ageof diagnosis of CRC in HNPCC.13 The variant allele of Aurora-A(A) has been associated with an increased risk of ovarian cancer,29

esophageal squamous cell carcinoma,30 breast cancer31 and a vari-ety of other cancer types, including CRC32 as well as a later age ofonset in HNPCC.12

The focus of this study has been on 2 genes involved in cell-cycle control, as they have been shown to be associated with theage of diagnosis of CRC in HNPCC patients.12,13,26 Our resultsdid not differ significantly with respect to the genotype frequen-cies in the original publications, but we were unable to show anysignificant association overall with the age of disease onset andgenotype. In addition, when the study population was divided onthe basis of hMLH1 or hMSH2 mutation carriers, no associationwith the T91A SNP in Aurora-A and age of disease onset wasobserved. The most likely explanation for previous results show-ing a positive relationship between the Aurora-A SNP and age of

TABLE II – MEDIAN AGE OF DIAGNOSIS OF CRC (AGE AT WHICH 50% OF THE POPULATION IS CANCER FREE) IN HNPCC PARTICIPANTSFOR AURORA-A AND CYCLIN D1; SUBJECT GROUP AND HMSH2 MUTATION CARRIERS

GenotypeSubject group1 hMSH22 carriers

Aurora-A Cyclin D1 Cyclin D1

Homozygote wildtype 48 years (n5 171) 47 years (n5 75) 72 years (n5 24)Heterozygote 47 years (n5 103) 49 years (n5 151) 48 years (n5 71)Homozygote variant 50 years (n5 14) 47 years (n5 72) 42 years (n5 35)

1The subject group includes 298 samples (14 samples without information about age were excluded).–2hMSH2 carriers include 130 samples(5 samples without information about age were excluded).

FIGURE 1 – Kaplan-Meier estimated by (a) Aurora-A genotype and(b) Cyclin D1 genotype genotype. The graph shows the effect thegenotypes have on age of diagnosis of CRC in HNPCC patients. Thereis no statistical significant difference between the genotypes when itcomes to age of diagnosis of CRC for any of the SNPs.

FIGURE 2 – Kaplan-Meier estimated by Cyclin D1 genotype inhMSH2 mutation carriers. The graph shows the effect the genotypeshave on age of diagnosis of CRC in HNPCC patients. There is a statis-tical significant difference between the genotypes when it comes toage of diagnosis of CRC (log-rank test: p 5 0.03, Wilcoxon test: p 50.03 and Tarone-Ware test: p5 0.02).

1275AURORA-A AND CYCLIN D1 POLYMORPHISMS

disease onset is the high likelihood of a Type 1 error occurring byvirtue of the limited population size used in the previous study(125 patients were studied, originating from 60 families12).

With respect to cyclin D1 and disease risk, a more complicatedrelationship with disease risk and the G870A SNP has beenobserved. Our studies indicate that there is a significant associa-tion between this SNP in cyclin D1 and hMSH2 mutation carriersand the age of CRC diagnosis. The first report of an associationwith an earlier onset of disease was based on a very limited num-ber of mutation positive cases (n 5 86), which was dominated byhMSH2 mutation carriers (57 hMSH2 carriers vs. 28 hMLH1 muta-tion carriers).13 A second group investigated 146 HNPCC patients,141 patients harbored the hMLH1 mutations and the remaining 5harbored hMSH2 mutations,26 and did not find the same relation-ship. Furthermore, a larger study from Germany33 failed to findany association between the G870A polymorphism and the age ofdisease onset in HNPCC. In our study, we have investigated 135and 177 hMSH2 and hMLH1 carriers, respectively. When allHNPCC cases are analyzed together, similar to Kruger et al.,33 wefailed to identify any association with the G870A SNP and the ageof diagnosis of CRC. If, however, the HNPCC cases are subdi-vided into hMLH1 or hMSH2 mutation carriers we observed a sig-nificant difference in the age of colorectal cancer onset in thehMSH2 carriers associated with the G870A SNP. In the study byKruger et al., the HNPCC population was not subdivided intohMLH1 or hMSH2 carriers,33 and we are therefore unable to com-pare directly this observation. Our observation that there is a rela-tionship between the G870A SNP and the age of diagnosis ofCRC suggests that there is an interaction between hMSH2 and

cyclin D1. However, there is little information in the literature tosupport a direct relationship, but it does not exclude this possibil-ity.

Potential limitations of the current study include populationstratification, which could be a confounder, but this should not beaffecting our results as we are searching for modifying polymor-phisms affecting disease expression in HNPCC patients (definedentity), but cannot be excluded. Environmental factors that are dif-ferent in the 2 countries could potentially affect the results. We donot believe this is the case, as it has been shown that for most ofthe common disease-associated polymorphisms, ethnicity is likelyto be a poor predictor of an individual’s genotype.34 The subjectgroups in this study have similar genotype frequencies (58, 37 and5% for Aurora-A and 24, 51 and 24% for Cyclin D1) to Caucasiancontrols (58, 35 and 6% for Aurora-A and 26, 48 and 26% forCyclin D1) and are not significantly different from the frequenciesreported in the study by Chen et al.12 The results could be due tomultiple statistical testing; however, the association of the CyclinD1 SNP with age of onset of CRC in hMSH2 mutation carriers isintriguing.

Although this study is one of the larger cohorts of HNPCCpatients examined, more HNPCC populations need to be studiedto confirm these results. Looking for modifying polymorphismsinfluencing disease expression has proven to be a difficult task, ascontroversial results seem to be the rule rather then the exception.Nevertheless, it is becoming evident that genetic modifiers of dis-ease risk in HNPCC do exist and have the potential to improvepredictive genetic counseling in this disorder.

References

1. Lawes DA, SenGupta SB, Boulos PB. Pathogenesis and clinical man-agement of hereditary non-polyposis colorectal cancer. Br J Surg2002;89:1357–69.

2. Lu K. Endometrial cancer in women with HNPCC. Int J GynecolCancer 2005;15:400–1.

3. Fishel R, Lescoe MK, Rao MR, Copeland NG, Jenkins NA, Garber J,Kane M, Kolodner R. The human mutator gene homolog MSH2 andits association with hereditary nonpolyposis colon cancer. Cell1993;75:1027–38.

4. Bronner CE, Baker SM, Morrison PT, Warren G, Smith LG, LescoeMK, Kane M, Earabino C, Lipford J, Lindblom A. Mutation in theDNA mismatch repair gene homologue hMLH1 is associated withhereditary non-polyposis colon cancer. Nature 1994;368:258–61.

5. Peltomaki P, Vasen HF. Mutations predisposing to hereditary nonpo-lyposis colorectal cancer: database and results of a collaborativestudy. The International Collaborative Group on Hereditary Nonpoly-posis Colorectal Cancer. Gastroenterology 1997;113:1146–58.

6. Peltomaki P. Deficient DNA mismatch repair: a common etiologicfactor for colon cancer. Hum Mol Genet 2001;10:735–40.

7. Scott RJ, McPhillips M, Meldrum CJ, Fitzgerald PE, Adams K, Spi-gelman AD, du Sart D, Tucker K, Kirk J. Hereditary nonpolyposiscolorectal cancer in 95 families: differences and similarities betweenmutation-positive and mutation-negative kindreds. Am J Hum Genet2001;68:118–27.

8. Heinimann K, Scott RJ, Chappuis P, Weber W, Muller H, Dobbie Z,Hutter P. N-acetyltransferase 2 influences cancer prevalence inhMLH1/hMSH2 mutation carriers. Cancer Res 1999;59:3038–40.

9. Talseth BA, Meldrum C, Suchy J, Kurzawski G, Lubinski J, Scott RJ.Genetic polymorphisms in xenobiotic clearance genes and their influ-ence on disease expression in hereditary nonpolyposis colorectal can-cer patients. Cancer Epidemiol Biomarkers Prev 2006;15:2307–10.

10. Zecevic M, Amos CI, Gu X, Campos IM, Jones JS, Lynch PM, Rodri-guez-Bigas MA, Frazier ML. IGF1 gene polymorphism and risk forhereditary nonpolyposis colorectal cancer. J Natl Cancer Inst2006;98:139–43.

11. Felix R, Bodmer W, Fearnhead NS, van der Merwe L, Goldberg P,Ramesar RS. GSTM1 and GSTT1 polymorphisms as modifiers of ageat diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC) ina homogeneous cohort of individuals carrying a single predisposingmutation. Mutat Res 2006;602:175–81.

12. Chen J, Sen S, Amos CI, Wei C, Jones JS, Lynch P, Frazier ML.Association between Aurora-A kinase polymorphisms and age ofonset of hereditary nonpolyposis colorectal cancer in a Caucasianpopulation. Mol Carcinog 2007;46:249–56.

13. Kong S, Amos CI, Luthra R, Lynch PM, Levin B, Frazier ML. Effectsof cyclin D1 polymorphism on age of onset of hereditary nonpolypo-sis colorectal cancer. Cancer Res 2000;60:249–52.

14. Sen S, Zhou H, Zhang RD, Yoon DS, Vakar-Lopez F, Ito S, Jiang F,Johnston D, Grossman HB, Ruifrok AC, Katz RL, Brinley W, et al.Amplification/overexpression of a mitotic kinase gene in human blad-der cancer. J Natl Cancer Inst 2002;94:1320–9.

15. Marumoto T, Hirota T, Morisaki T, Kunitoku N, Zhang D, IchikawaY, Sasayama T, Kuninaka S, Mimori T, Tamaki N, Kimura M, OkanoY, et al. Roles of aurora-A kinase in mitotic entry and G2 checkpointin mammalian cells. Genes Cells 2002;7:1173–82.

16. Bischoff JR, Anderson L, Zhu Y, Mossie K, Ng L, Souza B,Schreyver B, Flanagan P, Clairvoyant F, Ginther C, Chan CS,Novotny M, et al. A homologue of Drosophila aurora kinase is onco-genic and amplified in human colorectal cancers. EMBO J 1998;17:3052–65.

17. Li D, Zhu J, Firozi PF, Abbruzzese JL, Evans DB, Cleary K, Friess H,Sen S. Overexpression of oncogenic STK15/BTAK/Aurora A kinasein human pancreatic cancer. Clin Cancer Res 2003;9:991–7.

18. Miyoshi Y, Iwao K, Egawa C, Noguchi S. Association of centrosomalkinase STK15/BTAK mRNA expression with chromosomal instabil-ity in human breast cancers. Int J Cancer 2001;92:370–3.

19. Sen S, Zhou H,White RA. A putative serine/threonine kinase encodinggene BTAK on chromosome 20q13 is amplified and overexpressed inhuman breast cancer cell lines. Oncogene 1997;14:2195–200.

20. Tanaka T, Kimura M, Matsunaga K, Fukada D, Mori H, Okano Y.Centrosomal kinase AIK1 is overexpressed in invasive ductal carci-noma of the breast. Cancer Res 1999;59:2041–4.

21. Zhou H, Kuang J, Zhong L, Kuo WL, Gray JW, Sahin A, BrinkleyBR, Sen S. Tumour amplified kinase STK15/BTAK induces centro-some amplification, aneuploidy and transformation. Nat Genet1998;20:189–93.

22. Giet R, Petretti C, Prigent C. Aurora kinases, aneuploidy and cancer,a coincidence or a real link? Trends Cell Biol 2005;15:241–50.

23. Aquilina G, Crescenzi M, Bignami M. Mismatch repair, G(2)/M cellcycle arrest and lethality after DNA damage. Carcinogenesis1999;20:2317–26.

24. Donnellan R, Chetty R. Cyclin D1 and human neoplasia. Mol Pathol1998;51:1–7.

25. Betticher DC, Thatcher N, Altermatt HJ, Hoban P, Ryder WD, Heigh-way J. Alternate splicing produces a novel cyclin D1 transcript. Onco-gene 1995;11:1005–11.

26. Bala S, Peltomaki P. CYCLIN D1 as a genetic modifier in hereditarynonpolyposis colorectal cancer. Cancer Res 2001;61:6042–5.

1276 TALSETH ET AL.

27. Talseth BA, Meldrum C, Suchy J, Kurzawski G, Lubinski J, Scott RJ.Age of diagnosis of colorectal cancer in HNPCC patients is morecomplex than that predicted by R72P polymorphism in TP53. Int JCancer 2006;118:2479–84.

28. Matthias C, Branigan K, Jahnke V, Leder K, Haas J, Heighway J,Jones PW, Strange RC, Fryer AA, Hoban PR. Polymorphism withinthe cyclin D1 gene is associated with prognosis in patients with squa-mous cell carcinoma of the head and neck. Clin Cancer Res1998;4:2411–8.

29. Dicioccio RA, Song H, Waterfall C, Kimura MT, Nagase H, McGuireV, Hogdall E, Shah MN, Luben RN, Easton DF, Jacobs IJ, PonderBA, et al. STK15 polymorphisms and association with risk of inva-sive ovarian cancer. Cancer Epidemiol Biomarkers Prev 2004;13:1589–94.

30. Miao X, Sun T, Wang Y, Zhang X, Tan W, Lin D. Functional STK15Phe31Ile polymorphism is associated with the occurrence andadvanced disease status of esophageal squamous cell carcinoma. Can-cer Res 2004;64:2680–3.

31. Egan KM, Newcomb PA, Ambrosone CB, Trentham-Dietz A, Titus-Ernstoff L, Hampton JM, Kimura MT, Nagase H. STK15 polymor-phism and breast cancer risk in a population-based study. Carcinogen-esis 2004;25:2149–53.

32. Ewart-Toland A, Dai Q, Gao YT, Nagase H, Dunlop MG, FarringtonSM, Barnetson RA, Anton-Culver H, Peel D, Ziogas A, Lin D, MiaoX, et al. Aurora-A/STK15 T191A is a general low penetrance cancersusceptibility gene: a meta-analysis of multiple cancer types. Carcino-genesis 2005;26:1368–73.

33. Kruger S, Engel C, Bier A, Mangold E, Pagenstecher C, DoeberitzMK, Holinski-Feder E, Moeslein G, Keller G, Kunstmann E, FriedlW, Plaschke J, et al. Absence of association between cyclin D1(CCND1) G870A polymorphism and age of onset in hereditary non-polyposis colorectal cancer. Cancer Lett 2006;236:191–7.

34. Lohmueller KE, Wong LJ, Mauney MM, Jiang L, Felder RA, JosePA, Williams SM. Patterns of genetic variation in the hypertensioncandidate gene GRK4: ethnic variation and haplotype structure. AnnHum Genet 2006;70(Part 1):27–41.

1277AURORA-A AND CYCLIN D1 POLYMORPHISMS