Benign and malignant thyroid lesions show instability at microsatellite loci

Abstract

Forty-six benign and m alignant tum ours and tu m ou r-lik e lesions o f the thyroid were analysed for m icrosatellite instability (MI) at eight loci, m ap p in g to four different ch rom osom es, 7 lesio n s (15%) displayed MI at one or more loci, in clu d in g 2/13 nodular goitres, 2/15 follicular ad en om as, 2/12 papillary carcinom as and 1/4 follicular carcin o m as. Two benign and one m alignant lesio n am ong the seven unstable cases exhibited this p h en otyp e at three or m ore loci. We found no m u tation s in the m ism a tch repair gene, hMSH2, in the seven affected cases, after screening all th e exons by CDGE m utation analysis. At variance w ith the data on record, these results indicate that, despite being relatively infrequent, MI does occur n ot only in thyroid carcinom as but also in benign lesion s (goitres and follicular adenom as of the thyroid).

Microsatellite instability and its correlation with clinicopathological features in a series of thyroid tumors prevalent in iodine deficient areas

“…Higher incidence of MSI was observed using different panel of markers in malignant vs benign tumors (Stoler et al, 2002). Our present data is in concordance with the previous study using a different subset of markers (Soares et al, 1997). Another study described overall frequency of 21.5% in fifty-one thyroid tumors (Lazzereschi et al, 1999), which differs from ours.…”

“…A study based on small series of cases and limited number of microsatellite markers examined could not show any evidence of MSI (Farid et al, 1994;Alves et al, 2000) whereas other reports have been suggestive of limited role of MSI in both benign and malignant tumors using the different set of microsatellite markers (Soares et al, 1997;Zhou et al, 1997;Tomita et al, 1999). In our present study, 66.6% of thyroid tumors exhibited MSI/LOH on examining six mono and four dinucleotide microsatellite markers, including all the benign tumors.…”

“…In a series of nine cases no incidence of MSI was reported (Vermiglio et al, 1995) whereas limited incidence of MSI was observed in larger series of tumors (Soares et al, 1997). PCR based MSI analysis in thyroid tumors may allow identification of MMR status that can be further correlated with the risk groups that could help in deciding the extent of treatment in a particular patient.…”

Microsatellite instability in thyroid tumours and tumour-like lesions

“…The small series of nine cases reported by Vermiglio et al (1995) did not exhibit any MI, although a limited incidence of MI was observed in the larger series of tumours and tumour-like lesions analysed by Soares et al (1997). To explore the role of MI in thyroid carcinogenesis, we analysed the status of ten dinucleotide repeat microsatellite loci in a panel of 51 tumours and tumour-like lesions.…”

Foci formation of P53‐binding protein 1 in thyroid tumors: Activation of genomic instability during thyroid carcinogenesis

“…2 Thus, transfection of mutant HRAS V12 or mutant BRAF V600E induced GIN in a rat thyroid cell line, manifesting as loss of chromosomal material, mitotic bridge formation and misaligned chromosomes. [3][4][5] Recently, we found RET oncogene amplification in human thyroid cancers. 6 Oncogene amplification is common in solid tumors and correlates with a poor prognosis for patients with ovarian cancer (HER-2/neu), breast cancer (C-MYC, HER-2/neu), neuroblastoma (N-MYC), or small cell lung cancer (C-MYC).…”