A twisted kiss: in vitro and in vivo evidence of genetic variation and suppressed transcription of the metastasis-suppressor gene KiSS1 in early breast cancer.

UNLABELLED: KiSS-1 is ametastasis suppressor gene, its inactivation linked to advanced tumor stage and dismal prognosis. We studied its mutational status ,transcription and protein expression in human cancer cell lines and patients with early breast cancer.
Tumor tissue DNA and messenger RNA (mRNA) of KiSS1 exons III and IV from the human cancer cell lines Hela, Jurkat, A549, W138t, MCF-7 and from formalin-fixed resected breast adenocarcinomas from 50 women were analysed by means of PCR-SSCP, RT-PCR and sequencing. Tumor tissue was stained for KiSS1 protein expression by means of the streptavidin-biotin complex immunoperoxidase assay. Presence of KiSS1 mutation, mRNA levels and protein staining were examined for correlations with patient/tumor characteristics.
A transversion in exon IVa replacing cytosine with guanine was identified 242 base pairs from the translation start site (242C>G) in the cell lines MCF-7, A549 and in 5/50 tumors (10%), resulting in substitution of proline by arginine (P81R) and alteration of the protein tertiary structure. As the substitution was present in germ-line DNA in 3/5 breast cancer patients harbouring the polymorphism in their tumor, the incidence of tumour-specific somatic mutation was 4% among the 50 patiens with early breast cancer. Although the P81R substitution was associated with reduced KiSS1 protein immunoreactivity (56% in wild-type tumors versus 20% in KiSS1-variant tumours) and with axillary nodal involvement (55% in wild-type versus 80% in KiSS1-variant tumors), the correlations did not reach statistical significance. KiSS1 mRNA was detected in only 15/48 tumours (31%) and showed no correlation with mutation or protein expression. Twenty-six tumors stained for KiSS1 protein, in contrast to the universal strong staining seen in normal breast parenchyma and placental tissues. At amedian follow-up of 38 months, relapses occurred in 20% of women with non wild-type tumors versus 13% of women with wild-type KiSS1 tumors (p=0.7). Presence of KiSS1 mutation, mRNA levels and protein expression did not have prognostic significance for relapse-free survival.
In conclusion, altered nucleotide sequence and repression of transcription are two potential mechanisms of suppression of the anti-metastatic effects of KiSS1 in early breast cancer: Confirmation in larger cohorts and study of functional effects of the 242C>G exon IVa mutation are warranted. KEYWORDS: KiSS1, metastasis-suppressor gene, breast cancer, mutation, transcription.

The missing kiss of life: transcriptional activity of the metastasis suppressor gene KiSS1 in early breast cancer.

BACKGROUND: KiSS-1 is a metastasis suppressor gene encoding a neuropeptide with potent antimetastatic activities in tumour cell lines. The transcriptional activity of the gene and its associations in resected breast cancer were analysed. MATERIALS AND METHODS: Tumour messenger RNA (mRNA) of the KiSS1 exon I/II boundary was extracted from paraffin-embedded stage II or III node-positive breast adenocarcinomas of 272 women. KiSS1 mRNA was examined for associations with outcome, disease and molecular characteristics. RESULTS: Only 8 out of 272 tumours (3%) yielded detectable KiSS1 mRNA levels. There was no evidence of correlation of KiSS1 transcription with the number of involved axillary nodes, grade, hormone receptor status or tumour size. Of women with increased KiSS1 mRNA tumour levels, 87.5% were postmenopausal, whereas only 48% were postmenopausal among patients without detectable KiSS1 mRNA (p = 0.03). No association of KiSS1 transcription was found with transcription of the cell cycle-regulators HER2, VEGF, p53, BCL2, PAEP, or BIRC5. At a median follow-up of 62 months, there was no statistically significant difference between women harbouring KiSS1 mRNA-negative versus-positive tumours in terms of disease-free and overall survival (log-rank test p = 0.54 and p = 0.55, respectively). CONCLUSION: The metastasis suppressor gene KiSS1 is silenced in the vast majority of resected node-positive breast adenocarcinomas. These findings support the antimetastatic role of the gene and warrant its study as a prognostic marker and a therapeutic target.

Cavitating squamous cell lung carcinoma-distinct entity or not? Analysis of radiologic, histologic, and clinical features.

INTRODUCTION: Patients with cavitating squamous lung carcinoma (cSLC) are believed to harbor aggressive, chemoresistant disease with distinct features and fare poorly. We retrospectively analyzed radiologic, histologic, and clinical features of patients with cSLC and solid SLC (sSLC) from the patient registry of four Hellenic Cooperative Oncology Group (HeCOG) cancer centres in an effort to detect distinct characteristics of cSLC. PATIENTS AND METHODS: 37 cSLC and 212 sSLC patients, most of them male smokers, aged more than 60, treated with resection and/or chemotherapy/radiotherapy were included in the analysis. Disease stage, histologic differentiation and lymphatic/vascular invasion, pre-diagnosis symptoms and their duration, tumor size, site and associated features, metastatic sites, chemotherapy administered, responses and duration as well as time to treatment failure, and overall survival were analyzed for significant differences between the two patient groups. RESULTS: Statistically significant differences (two-sided P < 0.05) in patients with cSLC were found for: locally advanced (IIIB) or metastatic (IV) disease (76.5%) at presentation, longer duration of pre-diagnosis symptoms (mean 10 months), more frequent manifestation of fever, cough, weight loss, poor tumor differentiation, lower lobe primary, absence of atelectasis and satellite lesions. Objective response rates (33% for cSLC versus 32% for sSLC) and response duration (median 6 versus 5 months) were no different in the two patient groups. Median time to treatment failure (TTF) and overall survival (OS) were 10 and 13 months for cSLC patients, whereas 12 and 18 months for sSLC patients. Two-year TTF and OS rates were 18.5% and 33.5% for cSLC, while they were 19.3% and 40% for sSLC. No statistically significant differences were observed in any survival curves. CONCLUSION: Patients with cSLC present with high grade tumors that may initially simulate infectious processes, leading to late diagnosis despite long standing symptoms and presentation with advanced disease. In view of lack of evidence for differential disease course, increased chemoresistance and inferior outcome in comparison to sSLC patients, the definition of cavitating pulmonary carcinoma as a distinct clinical subentity cannot be supported.