These homologies suggest that PTEN may suppress tumor cell growth by antagonizing protein tyrosine kinases and may regulate tumor cell invasion and metastasis through interactions at focal adhesions.
The identification of the second mutational event in 10 (43%) tumors establishes PTEN/MMAC1 as a main inactivation target of 10q loss in sporadic prostate cancer.
PTEN, a candidate tumor suppressor gene located at chromosome 10q23.3, was recently identified and found to be homozygously deleted or mutated in several different types of human tumors.
Microsatellite analyses of normal-tumor DNA pairs were performed on 14 of these cases and revealed LOH at locations flanking and/or near PTEN/MMAC1 in all but 1 instance, suggesting that deletion of the remaining wild-type allele had occurred in the large majority of tumors with PTEN/MMAC1 mutations.
A novel gene was identified recently at chromosome 10q23, named PTEN or MMAC1, and based on several criteria it was designated as a potential human tumor suppressor gene.
This analysis suggest that PTEN gene mutations are restricted to high-grade adult gliomas and that this abnormality is independent of the presence or absence of gene amplification or p53 gene mutation in these tumors.
The susceptibility locus for both CS and BZS has recently been identified as the novel tumor suppressor gene PTEN, encoding a dual specificity phosphatase, located at 10q23.3.
In addition, in this set of tumor cell lines, we detected 11 (approximately 14%) homozygous deletions that eliminated coding portions of MMAC1, a class of abnormality not detected by our methods in primary tumors.
This patient's deletion contains the putative locus for Cowden syndrome and a recently discovered candidate tumor suppressor gene (MMAC1 or PTEN) that has been implicated in the progression of a variety of human malignancies.
We identified five PTEN mutations in 37 primary prostatic tumours analysed and found that 70% of tumours showed loss or alteration of at least one PTEN allele, supporting the evidence for PTEN involvement in prostate tumour progression.
The LOH identified in samples from individuals with CD and the suggestion of allelic loss and reduced transcription in hamartomas from a CD patient provide evidence that PTEN/MMACI functions as a tumor suppressor in CD.
The newly identified putative tumor suppressor gene PTEN, located at #10q23, might be responsible for the frequently observed allelic deletions from #10q23-25 in prostate cancer.
PCR-based single-stranded conformational variant analysis and sequencing of individual PTEN exons in 34 tumor specimens and their corresponding normal DNA were used.
Most recently, a putative tumor suppressor gene (PTEN/MMAC1) has been identified in the region between D10S215 and an adjacent, more telomeric marker (D10S541) and was found to be altered in breast cancers, prostate cancers, and glioblastomas.