PCR-SSCP-DNA Sequencing Method in Detecting PTEN Gene Mutation and its Significance in Human Breast Cancer in Turkish Populations
01 Jan 2012-Biotechnology & Biotechnological Equipment (Taylor & Francis)-Vol. 26, Iss: 5, pp 3220-3223
TL;DR: The PTEN protein expression in tissues with breast cancer indicated that the total positive rate of PTENprotein expression was 68% in breast cancer tissue, which was significantly lower than that in paracancerous tissues (P < 0.005).
Abstract: The aim of this study was to analyze the possible effect of PTEN gene mutations on the occurrence and development of human breast cancer. PCR-SSCP-DNA sequencing indicated that two kinds of mutation sites were found in 4 out of 80 breast cancer samples. One kind of mutation was found in exons. AA-TCC mutation was located 40 bp upstream of the 3'lateral exon 2 (115946 AA-TCC). Such mutations led to terminator formation at codon 267 of the PTEN gene. The other mutation was found in an intron, including a C-T point mutation 91 bp upstream of 2' lateral exon 2 (1903858 C-T). The PTEN protein expression in tissues with breast cancer indicated that the total positive rate of PTEN protein expression was 68% in breast cancer tissue, which was significantly lower than that (100%) in paracancerous tissues (P < 0.005). PTEN gene mutation may play an important role in the occurrence and development of breast cancer.
TL;DR: In this article, the effect of different functional groups on binding capacity of DNA was studied with bare and modified superparamagnetic iron oxide nanoparticles (SPIONs), where modifications were performed with [3-(2,3-epoxypropoxy)propyl] trimethoxy silane (GPTS) and (3-aminopropyl) triethoxysilane (APTS) by silanization reaction and also subsequent reaction with glutaraldehyde (GA) to obtain functional groups.
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TL;DR: A new probe based on immobilization of amino linked oligonucleotide (NH2-linked DNA) on poly(glycidyl methacrylate-co-vinylferrocene)-coated Pt electrode was fabricated for the electrochemical detection of PTEN gene from human prostate tissues and showed good selectivity toward target DNA sequence.
Abstract: In this study, a new probe based on immobilization of amino linked oligonucleotide (NH2-linked DNA) on poly(glycidyl methacrylate-co-vinylferrocene)-coated Pt electrode was fabricated for the electrochemical detection of PTEN gene from human prostate tissues. The experimental parameters such as DNA immobilization time, DNA concentration, and target concentration were optimized. The selectivity of the NH2-linked DNA probe was assessed with mismatch (MM) and noncomplementary (NC) sequences. The applicability of the NH2-linked DNA probe to the PCR amplified samples correspond to PTEN gene from prostate tissues was evaluated. The immobilization of DNA on the copolymer was confirmed by FTIR, AFM, CV and DPV analysis. The PCR products were also identified by using agarose gel electrophoresis. The prepared probe indicated a linear range (10–100 μg mL−1) with a detection limit (4.7 μg mL−1) and a good selectivity of the NH2-linked DNA probe toward target DNA sequence. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40638.
TL;DR: The PTEN product has a protein tyrosine phosphatase domain and extensive homology to tensin, a protein that interacts with actin filaments at focal adhesions as discussed by the authors.
Abstract: Mapping of homozygous deletions on human chromosome 10q23 has led to the isolation of a candidate tumor suppressor gene, PTEN, that appears to be mutated at considerable frequency in human cancers. In preliminary screens, mutations of PTEN were detected in 31% (13/42) of glioblastoma cell lines and xenografts, 100% (4/4) of prostate cancer cell lines, 6% (4/65) of breast cancer cell lines and xenografts, and 17% (3/18) of primary glioblastomas. The predicted PTEN product has a protein tyrosine phosphatase domain and extensive homology to tensin, a protein that interacts with actin filaments at focal adhesions. 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.
TL;DR: Mutational analysis of PTEN in CD kindreds has identified germline mutations that are predicted to disrupt the protein tyrosine/dual-specificity phosphatase domain of this gene, and implies that PTEN may play a role in organizing the relationship of different cell types within an organ during development.
Abstract: Cowden disease (CD) is an autosomal dominant cancer predisposition syndrome associated with an elevated risk for tumours of the breast, thyroid and skin1–2. Lhermitte-Duclos disease (LDD) cosegregates with a subset of CD families and is associated with macrocephaly, ataxia and dysplastic cerebellar gangliocytomatosis3–4. The common feature of these diseases is a predisposition to hamartomas, benign tumours containing differentiated but disorganized cells indigenous to the tissue of origin. Linkage analysis has determined that a single locus within chromosome 10q23 is likely to be responsible for both of these diseases5. A candidate tumour suppressor gene (PTEN) within this region is mutated in sporadic brain, breast and prostate cancer6. Another group has independently isolated the same gene, termed MMAC1, and also found somatic mutations throughout the gene in advanced sporadic cancers7. Mutational analysis of PTEN in CD kindreds has identified germline mutations in four of five families. We found nonsense and missense mutations that are predicted to disrupt the protein tyrosine/dual-specificity phosphatase domain of this gene. Thus, PTEN appears to behave as a tumour suppressor gene in the germline. Our data also imply that PTEN may play a role in organizing the relationship of different cell types within an organ during development.
TL;DR: Cowden disease (CD) (MIM 158350), or multiple hamartoma syndrome, is a rare autosomal dominant familial cancer syndrome with a high risk of breast cancer and central nervous system manifestations of CD were emphasized only recently.
Abstract: Cowden disease (CD) (MIM 158350), or multiple hamartoma syndrome, is a rare autosomal dominant familial cancer syndrome with a high risk of breast cancer. Its clinical features include a wide array of abnormalities but the main characteristics are hamartomas of the skin, breast, thyroid, oral mucosa and intestinal epithelium. The pathognomonic hamartomatous features of CD include multiple smooth facial papules, acral keratosis and multiple oral papillomas. The pathological hallmark of the facial papules are multiple trichilemmomas. Expression of the disease is variable and penetrance of the dermatological lesions is assumed to be virtually complete by the age of twenty. Central nervous system manifestations of CD were emphasized only recently and include megalencephaly, epilepsy and dysplastic gangliocytomas of the cerebellum (Lhermitte-Duclos disease, LDD). Early diagnosis is important since female patients with CD are at risk of developing breast cancer. Other lesions include benign and malignant disease of the thyroid, intestinal polyps and genitourinary abnormalities. To localize the gene for CD, an autosomal genome scan was performed. A total of 12 families were examined, resulting in a maximum lod score of 8.92 at theta = 0.02 with the marker D10S573 located on chromosome 10q22-23.
TL;DR: The mutational spectra of the PTEN/MMAC1 gene in tumors from various tissues, especially endometrium, brain, prostate, and ovary, are reviewed, suggesting that depending on the tissue type, the gene appears to be involved in the initiation or the progression of cancers.
Abstract: PTEN/MMAC1 (phosphatase, tensin homologue/mutated in multiple advanced cancers) is a tumor suppressor protein that has sequence homology with dual-specificity phosphatases, which are capable of dephosphorylating both tyrosine phosphate and serine/threonine phosphate residues on proteins. The in vivo function of PTEN/MMAC1 appears to be dephosphorylation of phosphotidylinositol 3,4, 5-triphosphate. The PTEN/MMAC1 gene is mutated in the germline of patients with rare autosomal dominant cancer syndromes and in subsets of specific cancers. Here we review the mutational spectra of the PTEN/MMAC1 gene in tumors from various tissues, especially endometrium, brain, prostate, and ovary, in which the gene is inactivated very frequently. Germline and somatic mutations in the PTEN/MMAC1 gene occur mostly in the protein coding region and involve the phosphatase domain and poly(A)(6) stretches. Compared with germline alterations found in the PTEN/MMAC1 gene, there is a substantially increased frequency of frameshift mutations in tumors. Glioblastomas and endometrial carcinomas appear to have distinct mutational spectra, probably reflecting differences in the underlying mechanisms of inactivation of the PTEN/MMAC1 gene in the two tissue types. Also, depending on the tissue type, the gene appears to be involved in the initiation or the progression of cancers. Further understanding of PTEN/MMAC1 gene mutations in different tumors and the physiologic consequences of these mutations is likely to open up new therapeutic opportunities for targeting this critical gene.
TL;DR: Data indicate that PTEN/MMAC1 is more commonly mutated than any other known gene in endometrial cancers, and may be responsible for several familial neoplastic disorders.
Abstract: Endometrial carcinomas represent the most common gynecological cancer in the United States, yet the molecular genetic events that underlie the development of these tumors remain obscure Chromosome 10 is implicated in the pathogenesis of endometrial carcinoma based on loss of heterozygosity (LOH), comparative genomic hybridization, and cytogenetics Recently, a potential tumor suppressor gene, PTEN/MMAC1 , with homology to dual-specificity phosphatases and to the cytoskeletal proteins tensin and auxillin was identified on chromosome 10 This gene is mutated in several types of advanced tumors that display frequent LOH on chromosome 10, most notably glioblastomas Additionally, germ-line mutations of PTEN/MMAC1 are responsible for several familial neoplastic disorders, including Cowden disease and Bannayan-Zonana syndrome Because this locus is included in the region of LOH in many endometrial carcinomas, we examined 70 endometrial carcinomas for alterations in PTEN/MMAC1 Somatic mutations were detected in 24 cases (34%) including 21 cases that resulted in premature truncation of the protein, 2 tumors with missense alterations in the conserved phosphatase domain, and 1 tumor with a large insertion These data indicate that PTEN/MMAC1 is more commonly mutated than any other known gene in endometrial cancers