• Title/Summary/Keyword: p53 mutations

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Prognostic Value of p53 Overexpression in Patients with Pathologic Stage I Non-small Cell Lung Cancer (제 1기 비소세포폐암 환자에서 p53 과발현과 예후의 관계)

  • Um, Sang-Won;Kim, Hojoong;Kwon, O Jung;Han, Joungho;Shim, Young Mog
    • Tuberculosis and Respiratory Diseases
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    • v.65 no.6
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    • pp.487-494
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    • 2008
  • Background: Chromosome 17p allele losses and mutations of p53 gene are the most common genetic abnormalities in lung cancer. The purposes of this study were to evaluate the factors associated with p53 protein overexpression and to evaluate its prognostic value in patients with pathologic stage I non-small cell lung cancer (NSCLC). Methods: This is a retrospective review for the patients who underwent surgical resection at Samsung Medical Center between Jan 2003 and Jun 2004. Immunohistochemical staining for p53 protein was performed on tumor tissues from patients with lung cancer. The p53 overexpression was evaluated in relation to age, sex, smoking history, histology and pathologic stage by univariate and multivariate analyses. The disease-free survival (DFS), disease-specific survival (DSS) and overall survival (OS) were analyzed using the Kaplan-Meier methods and the differences in DFS, DSS and OS were assessed by using the log-rank tests. Results: A total of 125 patients were included in the analysis and a median frequency of p53 expression in tumor tissue was 10%. The p53 overexpression (${\geq}10%$) was more common in squamous cell carcinoma (66%) than in adenocarcinoma (38%, p=0.002). The p53 overexpression was more common in pathologic stage IB (59%) than in IA (38%, p=0.002). Patients with p53-overexpressing tumor (27 years) smoked more years compared with those without it (20 years, p=0.032). Smoking history ${\geq}25$ pack-years was more common in patients with p53 overexpression (58%) than in those without it (38%, p=0.024). In the multivariate analysis, only histology was significantly associated with p53 overexpression. However, there were no significant differences of DFS, DSS and OS in relation to p53 status. Conclusion: The p53 overexpression was associated with histology, pathologic stage and smoking history in patients with pathologic stage I NSCLC. However, the p53 overexpression was not associated with patient's survival.

Impact of Cellular Genetic Make-up on Colorectal Cancer Cell Lines Response to Ellagic Acid: Implications of small interfering RNA

  • Yousef, Amany I;El-Masry, Omar S;Abdel Mohsen, Mohamed A
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.743-748
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    • 2016
  • Background: $K^-Ras$ activation is an early event in colorectal carcinogenesis and associated mutations have been reported in about 40% of colorectal cancer patients. These mutations have always been responsible for enhancing malignancy and silencing them is associated with attenuation of tumorigenicity. Among downstream effectors are the RAF/MEK/ERK and the PI3K/Akt signaling pathways. PI3K/Akt signaling leads to reduction of apoptosis, stimulated cell growth and enhanced proliferation. Ellagic acid (EA), a naturally occurring antioxidant, has recently emerged as a promising anti-cancer agent. Purpose: To evaluate the impact of cellular genetic makeup of two colon cancer cell lines with different genetic backgrounds, HCT-116 ($K^-Ras^-/p53^+$) and Caco-2 ($K^-Ras^+/p53^-$), on response to potential anti-tumour effects of EA. In addition, the influence of $K^-Ras$ silencing in HCT-116 cells was investigated. Materials and Methods: Cellular proliferation, morphology and cell cycle analysis were carried out in addition to Western blotting for detecting total Akt and p-Akt (at Thr308 and Ser473) in the presence and absence of different concentrations of EA. Cell proliferation was also assessed in cells transfected with different concentrations of $K^-Ras$ siRNA or incubated with ellagic acid following transfection. Results: The results of the present study revealed that EA exerts anti-proliferative and dose-dependent pro-apoptotic effects. Cytostatic and cytotoxic effects were also observed. p-Akt (at Thr308 and Ser473) was downregulated. Moreover, EA treatment was found to (i) reduce $K^-Ras$ protein expression; (ii) in cells transfected with siRNA and co-treated with EA, pronounced anti-proliferative effects as well as depletion of p-Akt (at Thr308) were detected. Conclusions: Cellular genetic makeup ($K^-Ras^-/p53^-$) was not likely to impose limitations on targeting EA in treatment of colon cancer. EA had a multi-disciplinary pro-apoptotic anti-proliferative approach, having inhibited Akt phosphorylation, induced cell cycle arrest and showed an anti-proliferative potential in HCT-116 cells (expressing mutant $K^-Ras$).

Mutantional analysis of tumor suppressor gene p53 in human oral squamous carcinoma cell line YD-9

  • Min, Ji-Hak;Kim, Do-Kyun;Lee, Moo-Hyung;Bae, Moon-Kyoung;Um, Kyung-Il;Kwak, Hyun-Ho;Park, Bong-Soo;Kim, Gyoo-Cheon
    • International Journal of Oral Biology
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    • v.32 no.2
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    • pp.79-84
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    • 2007
  • Oral squamous carcinoma (OSC) is the most common malignant neoplasm of the oral mucosa. Although the etiology of OSC is not fully understood, accumulated evidences indicate that the activation of proto-oncogenes and the inactivation of tumor suppressor genes underlie the disease development. An OSC cell line, YD-9 was newly established and characterized. However, the mutational analysis of p53 gene was not performed. Thus, in this study, the presence of mutation in the p53 gene was examined by amplification of exon-4 to -8 and subsequent DNA sequencing. Two point mutations were found in exon-4 and -6: A to G, resulting in amino acid change Tyr to Cys in exon-4, and C to G, resulting in amino acid change Gly to Arg in exon-6, respectively. Any mutation was not found in the exon-5, -7 and -8. The presented results would contribute to basic research to understand the biological mechanism of OSC using YD-9 cells.

PCR-SSCP Polymorphism of Inhibin ${\beta}_A$ Gene in Some Sheep Breeds

  • Chu, M.X.;Xiao, C.T.;Fu, Y.;Fang, L.;Ye, S.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.7
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    • pp.1023-1029
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    • 2007
  • Inhibins participate in the regulation of pituitary follicle-stimulating hormone synthesis and secretion, follicular maturation and steroidogenesis in the female. Inhibin ${\beta}_A$ gene (INHBA) was studied as a candidate gene for the prolificacy of sheep. Single nucleotide polymorphisms of the entire coding region and partial 3' untranslated region of INHBA were detected by PCR-SSCP in two high fecundity breeds (Small Tail Han and Hu sheep) and six low fecundity breeds (Dorset, Texel, German Mutton Merino, South African Mutton Merino, Chinese Merino and Corriedale sheep). Only the PCR products amplified by primers 3, 4 and 5 displayed polymorphisms. For primer 3, genotype CC was only detected in Chinese Merino sheep, genotype AA was detected in the other seven sheep breeds. Genotype BB was only detected in Hu sheep. Only Hu sheep displayed polymorphism. Eight or four nucleotide mutations were revealed between BB or CC and AA, respectively, and these mutations did not result in any amino acid change. For primer 4, genotypes EE, EG and GG were detected in Dorset and German Mutton Merino sheep, genotypes EE, EF and FF were detected in Chinese Merino sheep, only genotype EE was detected in the other five sheep breeds. Only Dorset, German Mutton Merino and Chinese Merino sheep displayed polymorphism. Sequencing revealed one nucleotide mutation ($114G{\rightarrow}A$) of exon 2 of INHBA gene between genotype FF and genotype EE, and this mutation did not cause any amino acid change. Another nucleotide change ($143C{\rightarrow}T$) was identified between genotype GG and genotype EE, and this mutation resulted in an amino acid change of $serine{\rightarrow}leucine$. For primer 5, genotypes KK and KL were detected in German Mutton Merino and Corriedale sheep, genotypes KK, LL and KL were detected in the other six sheep breeds. Genotype MM was only detected in Hu sheep. All of these eight sheep breeds displayed polymorphism. Sequencing revealed one nucleotide mutation ($218A{\rightarrow}G$) of exon 2 of the INHBA gene between genotype LL and genotype KK, and nine nucleotide mutations between genotype MM and genotype KK. These mutations did not alter amino acid sequence. The partial sequence (395 bp for exon 1 and 933 bp for exon 2) of the INHBA gene in Small Tail Han sheep (with genotype KK for primer 5) was submitted into GenBank (accession number EF192431). Small Tail Han sheep displayed polymorphisms only in the fragment amplified by primer 5. The Small Tail Han ewes with genotype LL had 0.53 (p<0.05) or 0.63 (p<0.05) more lambs than those with genotype KL or KK, respectively. The Small Tail Han ewes with genotype KL had 0.10 (p>0.05) more lambs than those with genotype KK.

Endometriosis, Leiomyoma and Adenomyosis: the Risk of Gynecologic Malignancy

  • Verit, Fatma Ferda;Yucel, Oguz
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5589-5597
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    • 2013
  • The aim of this review article was to evaluate the relationship and the possible etiological mechanisms between endometriosis, leiomyoma (LM) and adenomyosis and gynecological cancers, such as ovarian and endometrial cancer and leiomyosarcoma (LMS). MEDLINE was searched for all articles written in the English literature from July 1966 to May 2013. Reports were collected systematically and all the references were also reviewed. Malignant transformation of gynecologic benign diseases such as endometriosis, adenomyosis and LM to ovarian and endometrial cancer remains unclear. Hormonal factors, inflammation, familial predisposition, genetic alterations, growth factors, diet, altered immune system, environmental factors and oxidative stress may be causative factors in carcinogenesis. Early menarche, low parity, late menopause and infertility have also been implicated in the pathogenesis of these cancers. Ovarian cancers and endometriosis have been shown to have common genetic alterations such as loss of heterozygosity (LOH), PTEN, p53, ARID1A mutations. MicroRNAs have also been implicated in malignant transformation. Inflammation releases proinflammatory cytokines, and activates tumor associated macrophages (TAMS) and nuclear factor kappa b (NF-KB) signaling pathways that promote genetic mutations and carcinogenesis. MED12 mutations in LM and smooth muscle tumors of undetermined malignant potential (STUMP) may contribute to malignant transformation to LMS. A hyperestrogenic state may be shared in common with pathogenesis of adenomyosis, LM and endometrial cancer. However, the effect of these benign gynecologic diseases on endometrial cancer should be studied in detail. This review study indicates that endometriosis, LM, adenomyosis may be associated with increased risk of gynecological cancers such as endometrial and ovarian cancers. The patients who have these gynecological benign diseases should be counseled about the future risks of developing cancer. Further studies are needed to investigate the relationship between STUMPs, LMS and LM and characteristics and outcome endometrial carcinoma in adenomyotic patients.

Tissue Transglutaminase is Not Involved in the Aggregate Formation of Stably Expressed $\alpha$-Synuclein in SH-SY5Y Human Neuroblastoma Cells

  • Suh, Myung-Duk;Park, Chang-Ha;Kim, Sung-Soo;Kil, Myeng-Og;Lee, Geon-Hee;Johnson, Gail V. W.;Chun, Wan-Joo
    • Archives of Pharmacal Research
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    • v.27 no.8
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    • pp.850-856
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    • 2004
  • Intraneuronal deposition containing $\alpha$-synuclein is implicated in the pathogenesis of synuclein-opathies including Parkinsons disease (PD). Although it has been demonstrated that cytoplas-mic inclusions of wild type $\alpha$-synuclein are observed in the brain of PD patients and that $\alpha$-synuclein mutations such as A30P and A53T accelerate aggregate formation, the exact mech-anism by which $\alpha$-synuclein forms insoluble aggregates is still controversial. In the present study, to understand the possible involvement of tissue transglutaminase (tTG) in aggregate formation of $\alpha$-synuclein, SH-SY5Y cell lines stably expressing wild type or mutant (A30P or A53T) $\alpha$-synuclein were created and aggregate formation of $\alpha$-synuclein was observed upon activation of tTG. The data demonstrated that $\alpha$-synuclein negligibly interacted with tTG and that activation of tTG did not result in the aggregate formation of $\alpha$-synuclein in SH-SY5Y cells overexpressing either wild type or mutant $\alpha$-synuclein. In addition, $\alpha$-synuclein was not modi-fied by activated tTG in situ. These data suggest that tTG is unlikely to be a contributing factor to the formation of aggregates of $\alpha$-synuclein in a stable cell model.

The TP53 intron 6 G13964C Polymorphism and Risk of Thyroid and Breast Cancer Development in the Iranian Azeri Population

  • Dehghan, Roghayeh;Feizi, Mohammad Ali Hosseinpour;Pouladi, Nasser;Adampourezare, Mina;Farajzadeh, Davoud
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.3073-3077
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    • 2015
  • Background: TP53 mutations are the most common genetic alterations in human cancers. There are also several polymorphisms in both exons and introns of TP53 that may influence its anti-tumor functions and increase the risk of cancer development. Associations of the TP53 intron 6 G13964C polymorphism with increased risk of development of several cancers have been investigated in numerous studies, but the results were controversial and conflicting. In this study, we aimed to investigate the probable association of this polymorphism with risk of both thyroid and breast cancers among the Iranian-Azeri population. Materials and Methods: We performed two separate case control studies on associations of the intron 6 polymorphism with two different kinds of cancer. In one case-control study, a total of 75 patients with thyroid carcinoma and 180 controls were analyzed and the other study included 170 patients with breast cancer and 135 healthy women. The intron 6 genotype was determined by RFLP-PCR and the SPSS 16 program was applied for data analysis. Results: For thyroid cancer, the frequencies of GG genotype were 96.0% in patients and 93.3% in controls. The GC genotype had a frequency of 4.0 % in patients and 6.7% in controls. In the study on breast cancer, the frequency of GG and GC genotypes in patients were 95.3% and 4.7%, respectively. In breast related control group, the frequency of GG genotype was 93.3 % and the frequency of GC genotype was 6.7%. None of the cases and controls had the CC genotype. Conclusions: There was no significant association between the TP53 intron 6 G13964C polymorphism and risk of development of both thyroid and breast cancer in Iranian-Azeri patients.

Comprehensive Mutation Analysis of PIK3CA, p14ARF, p16INK4a and p21Waf1/Cip1 Genes is Suggestive of a Non- Neoplastic Nature of Phenytoin Induced Gingival Overgrowth

  • Swamikannu, Bhuminathan;Kumar, Kishore S.;Jayesh, Raghavendra S.;Rajendran, Senthilnathan;Muthupalani, Rajendran Shanmugam;Ramanathan, Arvind
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.2743-2746
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    • 2013
  • Background: Dilantin sodium (phenytoin) is an antiepileptic drug, which is routinely used to control generalized tonic clonic seizure and partial seizure episodes. A few case reports of oral squamous cell carcinomas arising from regions of phenytoin induced gingival overgrowth (GO), and overexpression of mitogenic factors and p53 have presented this condition as a pathology with potential to transform into malignancy. We recently investigated the genetic status of p53 and H-ras, which are known to be frequently mutated in Indian oral carcinomas in GO tissues and found them to only contain wild type sequences, which suggested a non-neoplastic nature of phenytoin induced GO. However, besides p53 and H-ras, other oncogenes and tumor suppressors such as PIK3CA, p14ARF, p16INK4a and $p21^{Waf1/Cip1}$, are frequently altered in oral squamous cell carcinoma, and hence are required to be analyzed in phenytoin induced GO tissues to be affirmative of its non-neoplastic nature. Methods: 100ng of chromosomal DNA isolated from twenty gingival overgrowth tissues were amplified with primers for exons 9 and 20 of PIK3CA, exons $1{\alpha}$, $1{\beta}$ and 2 of p16INK4a and p14ARF, and exon 2 of $p21^{Waf1/Cip1}$, in independent reactions. PCR amplicons were subsequently gel purified and eluted products were sequenced. Results: Sequencing analysis of the twenty samples of phenytoin induced gingival growth showed no mutations in the analyzed exons of PIK3CA, p14ARF, p16INK4a and $p21^{Waf1/Cip1}$. Conclusion: The present data indicate that the mutational alterations of genes, PIK3CA, p14ARF, p16INK4a and $p21^{Waf1/Cip1}$ that are frequently mutated in oral squamous cell carcinomas are rare in phenytoin induced gingival growth. Thus the findings provide further evidence that phenytoin induced gingival overgrowth as a non-neoplastic lesion, which may be considered as clinically significant given the fact that the epileptic patients are routinely administered with phenytoin for the rest of their lives to control seizure episodes.

Genetic Alteration of Tumor Suppressor Gene and Microsatellite in Nonsmall Cell Lung Cancer (비소세포폐암에서 종양억제유전자와 극소위성 변이에 관한 연구)

  • Shin, Tae-Rim;Hong, Young-Sook;Kim, Jhin-Gook;Chang, Jung-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.4
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    • pp.453-465
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    • 2000
  • Background : Lung carcinogenesis is a multistage process involving alterations in multiple genes and diverse pathway. Mutational activation of oncogenes and inactivation of tumor suppressor genes, and subsequent increased genetic instability are the major genetic events. The p53 gene and FHIT gene as tumor suppressor genes contribute to the pathogenesis of lung cancer, evidenced by mutation, microsatellite instability(MI) and loss of heterozygosity(LOH). Methods : We analysed genetic mutations of p53 and FHIT gene in 29 surgical specimens of nonsmall cell lung cancer using PCR-single strand conformation polymorphism, DNA sequencing and RT-PCR. MI and LOH were analyzed in loci of D3S1285, D9S171, and TP53. Results : In 2 cases, point mutation of p53 gene was observed on exon 5. MI of 3 times and LOH of 14 times were observed in at least one locus. In terms of the location of microsatellite, D3S1285 as a marker of FH1T was observed in 5 cases out of 26 specimens; D9S171 as a marker of p16 in 5 out of 17; and TP53 as a marker of p53 in 7 out of 27. In view of histologic type, squamous cell carcinoma presented higher frequency of microsatellite alteration, compared to others. Mutation of FHIT gene was observed in 11 cases and 6 cases of those were point mutation as a silent substitution on exon 8. FHIT mRNA expression exhibited deletion on exon 6 to 9 in 4 cases among 15 specimens, presenting beta-actin normally. Conclusion : Our results show comparable frequency of genetic alteration in nonsmall cell lung cancer to previous studies of Western countries. Microsatellite analysis might have a role as a tumor marker especially in squamous cell carcinoma. Understanding molecular abnormalities involved in the pathogenesis could potentially lead to prevention, earlier diagnosis and the development of novel investigational approaches to the treatment of lung cancer.

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