• Korean Journal of Clinical Laboratory Science
• /
• v.39 no.2
• /
• pp.128-135
• /
• 2007

This study was designed to investigate the correlation between the expression rate of p53 and p21 proteins by immunohistochemical staining and tumor prognostic factors including the tumor size, histological differentiation and Dukes' stage of tumor prognostic factors in colon cancer, and to acquire necessary data for the presumption of diagnosis, treatment and prognosis of colon cancer patients. From January 2000 to January 2003 at Hanyang University Guri Hospital, the paraffin blocks of 35 patients diagnosed with colon cancer whose pathologic reports were possible to review were selected. Harris hematoxylin & eosin (H&E) staining and immunohistochemical staining by ABC (Avidin Biotin Conjugate) method were performed. The histological differentiation grade and stage were classified according to the classification of the World Health Organization (WHO) and modified Dukes's stage from H&E staining. The expression rate of p53 and p21 proteins were analyzed by immunohistochemical staining. The results was analyzed statistically by SPSS (Windows version 8.0). As a result, the expression rate of p53 protein was 11.4% (4 cases) in clear differentiation, 48.6% (17 cases) in moderate differentiation, and 17.1% (6 cases) in poor differentiation. In other words, the poorer the differentiation, the higher the expression rate of p53 protein (p<0.05). The expression rate of p21 was 17.1% (6 cases) in clear differentiation, 40.0%(14 cases) in moderate differentiation, and 8.6% (3 cases) in poor differentiation, According to the progression of histological malignant degeneration, the expression rate of p21 protein decreased distinctively (p<0.05). However, the correlation between the two above mentioned proteins and the tumor-size and Dukes' stage was not of statistical significance. In the comparison of the expression rate of p53 protein with that of p21 protein, in 10 cases, p53 protein expression was positive while p21 protein expression was negative, and in 6 cases, p53 protein expression was negative whereas p21 protein expression was positive. Consequently a statistically significant inverse correlation between the expression rate of p53 protein and that of p21 protein was observed (p<0.05). In conclusion, we found a significant correlation between histological differentiation and the expression rate of p53 and p21 proteins (p<0.05), and a significant inverse correlation between the expression rate of p53 protein and that of p21 protein (p<0.05). Also, it could be confirmed that the over expression of p53 and p21 proteins is closely associated with the occurrence of colon cancer and its progress. Therefore, it is thought that this study may be greatly beneficial to the presumption of diagnosis, treatment and prognosis of colon cancer patients.

• The Korean Journal of Cytopathology
• /
• v.6 no.1
• /
• pp.1-9
• /
• 1995

This study was carried out to determine the usefulness of imprint cytology for detecting p53 protein in breast carcinoma. NCL-DO7 (Novocastra, U.K.) was used to detect p53 protein immunocytochemically. A total of 33 cases was studied, Immunostaining of imprint cytology with NCL-DO7 was positive in 64% (21/33) and showed relatively high coincident rate (80%) with immunostaining of formalin-fixed, paraffin-embedded specimen p53 protein was related to negative estrogen receptor status, but not to the nuclear grade, lymph node metastasis, or tumor size. The fact that p53 protein expression was not related to nuclear grade might be due to predominance of nuclear grade 3. It was easier to determine the nuclear grade is one of the most important prognostic factors, in imprint cytology than in tissue specimen. p53 protein tended to be stained more strongly in imprint cytology than in tissue. It is concluded that the application of imprint cytology in p53 protein detection can be performed easily, and that it may contribute to the evaluation of prognostic factors in breast carcinoma.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.5
• /
• pp.2341-2344
• /
• 2014

Background: p53 protein expression has been detected immunohistochemically in papillary thyroid carcinoma(PTC). We investigated the relations between its expression and clinicopathologic features and its significance as a diagnostic marker. Materials and Methods: We compared and evaluated 93 patients in whom thyroidectomy with lymph node dissection had been performed to treat PTC for clinicopathologic significance and 102 patients with 23 papillary thyroid overt carcinomas (POC), 57 papillary thyroid microcarcinomas(PMC), 5 follicular adenomas (FA), 5 Hashimoto's thyroiditis (HT) and 12 nodular hyperplasias (NH) for significance as a diagnostic marker. Expression of p53 protein was evaluated immunohistochemically in sections of paraffinembedded tissue. Results: Statistical analysis showed significantly different expression of p53 in PTC versus other benign thyroid lesions (BTL).The diagnostic sensitivity and specificity were 85.0% and 72.7%, respectively. Overexpression of p53 protein was observed in 44 of the 93 PTC cases (47.3%), but no significant correlation between p53 protein overexpression and clinicopathologic features (age, size, multiplicity, lymph node metastasis, extrathyroidal extension and vascular invasion) was noted. Conclusions: p53 is valuable to distinguish PTC from other BTL, but there is no correlation between p53 protein overexpression and clinicopathologic features.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.5
• /
• pp.844-848
• /
• 2002

In more than half of human tumors, the p53 tumor suppressor gene is mutated. Thus, restoration of wild-type p53 activity by repair of mutant RNA could be a potentially promissing approach to cancer treatment. To explore the potential use of RNA repair for cancer therapy, trans-splicing group I ribozymes were developed that could replace mutant p53 RNA with RNA sequence attached to the 3'end of ribozymes. By employing a mapping library of ribozymes, we first determined which regions of the p53 RNA are accessible to ribozymes, and found that the leader sequences upstream of the AUG start codon appeared to be particularly accessible. Next, trans-splicing ribozymes were generated that specifically recognized the sequences around these accessible regions. Subsequently, the ribozymes reacted with and altered the p53 transcripts by transferring a 3'exon tag sequence onto the targeted p53 RNA with high fidelity. Thus, these ribozymes could be utilized to repair mutant p53 in tumors, which would revert the neoplastic phenotype.

• Journal of Veterinary Clinics
• /
• v.19 no.2
• /
• pp.195-198
• /
• 2002

To identify mutations in exons 5 to 8 of the p53 tumor suppressor gene, we have analysed in 12 spontaneous canine tumors. In a malignant mast cell tumor, a 1 base pair alteration AGT $\longrightarrow$AGC (silent point mutation, serine) in codon 249 in exon 8 was detected. And the mammary gland adenocarcinoma was found to have a mis-sense point mutation (CCT $\longrightarrow$ TCT) in codon 285 in exon 8.

• Molecules and Cells
• /
• v.21 no.2
• /
• pp.218-223
• /
• 2006

The effect of poly(ADP-ribosyl)ation on the stability of p53 in SK-HEP1 cells treated with UV light was examined. Intracellular levels of p53 increased in cells treated with a low dose of UV light ($20J/m^2$), whereas they increased but then declined after a higher dose of UV ($100J/m^2$). Intracellular levels of p53 in the UV treated SK-HEP1 cells were dependent on the UV dose. Use of proteasome inhibitors revealed that p53 is degraded by proteasomal proteolysis after high doses of UV light. We present evidence that, at low doses, poly(ADP-ribose)polymerase (PARP) poly(ADP-ribosyl) ates p53 and protects it from proteasomal degradation before caspase-3 is activated, whereas at high doses the cells undergo UV induced apoptosis and PARP is cleaved by caspase-3 before it can protect p53 from degradation. Destabilization of p53 by cleavage of PARP may be important in cell fate decision favoring apoptosis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.7
• /
• pp.4295-4299
• /
• 2013

Background: Pretreatment serum p53 and epidermal growth factor receptor (EGFR) were assessed using enzyme-linked immunosorbent assay (ELISA) in patients with acute leukemia to analysis their roles in characterization of different subtypes of the disease. Materials and Methods: Serum samples from thirty two patients with acute myeloid leukemia (AML) and fourteen patients with acute lymphoid leukemia (ALL) were analysed, along with 24 from healthy individuals used as a control group. Results: The results demonstrated a significant increase of serum p53 and EGFR in patients with AML (p<0.0001) compared to the control group. Also, the results showed a significant increase of both markers in patients with ALL (p<0.05, p<0.0001 respectively). Sensitivities and specificities for these variables were 52% and 100% for p53, and 73.9%, 95.8% for EGFR. Serum p53 and EGFR could successfully differentiate between M4 and other AML subtypes, while these variables failed to discriminate among ALL subtypes. A positive significant correlation was noted between p53 and EGFR. Negative significant correlations were observed between these variables and both of hemoglobin (Hg) content and RBC count. Conclusions: Mutant p53 and EGFR are helpful serological markers for diagnosis of patients with AML or ALL and can aid in characterization of disease. Moreover, these markers may reflect carcinogenesis mechanisms.

• Korean Journal of Head & Neck Oncology
• /
• v.21 no.2
• /
• pp.139-145
• /
• 2005

Background and Objectives: Because of squamous cell carcinoma of the head and neck undergoes a generally poor hospital course, the prognostic significance of the squamous cell carcinomas in head and neck have been evaluated to identify those features associated with aggressive biologic behavior according to the immunologic and histopathologic characteristics. Materials and Method: To assess the significance of EGFR, c-erbB-2, p21 and p53 protein in head and neck tumors and their correlation with prognostic factors, samples from 74 patients with squamous cell carcinomas of larynx, pharynx, and oral cavity were studied immunohistochemically. Results: EGFR, c-erbB-2, p21, and p53 protein were expressed 94.6%, 24.3%, 85.1%, and 55.4% in 74 cases of head and neck squamous cell carcinoma, respectively. The positive expression of EGFR was associated significantly with clinical stage and the negative expressions of p21 was associated significantly with histopathologic differentiation. There were no significant relationships between the reactivity of EGFR, c-erbB-2, p21, and p53 protein. Conclusion: The expression of EGFR, c-erbB-2, p21 and p53 protein could be related to oncogenesis, and the expression of p21 and EGFR protein can be used as a prognosticator in head and neck squamous cell carcinoma under certain limitations, but c-erbB-2 and p53 protein expression alone is not enough for evaluating prognosis of the carcinoma.

• The Korean Journal of Cytopathology
• /
• v.7 no.2
• /
• pp.144-150
• /
• 1996

Although bladder cancers are very common, little is known about their molecular pathogenesis. It is known that p53 alteration is found in about 60% of muscle-invasive bladder cancer, necessiating aggressive therapy and poor outcome. We examined the nuclear expression of p53 protein, using D07 monoclonal antibody in the urine samples from 31 patients with transitional cell carcinoma of the bladder to investigate the correlation of p53 overexpression with histologic grades and depth of invasion. The positive rate of p53 protein was 27% in superficial bladder tumor, but increased up to 71% in the invasive bladder carcinomas. The overexpression of p53 protein increased according to Mostofi grading system from 18% in grade I, 45% in grade II, and up to 100% in grade III. The p53 expression tended to be higher in the invasive and high grade bladder cancers than in the superficial and low grade ones(p<0.05). These results suggest that immunohistochemical analysis of the urine specimen in the bladder cancer patients could be a useful method of screening for the presence of p53 mutant protein. The mutant p53 protein expression may be an indicator of bladder cancer with more proliferative potential and/or aggressive biologic behavior.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.17
• /
• pp.7413-7417
• /
• 2014

Background: Development of gastric cancer (GC) is a multistep process that requires alterations in the expression of oncogenes and tumor suppressor genes, occurring over several decades. The p53 tumor suppressor protein is involved in cell-cycle control, apoptosis and DNA repair. One of the most important regulators of p53 is MDM2, which acts as a negative regulator in the p53 pathway. Based on the key role of p53 and MDM2 in tumor suppression, polymorphisms that cause change in their function might affect cancer risk. We therefore elevated associations of the polymorphisms of p53 (R72P) and MDM2 (SNP309) with GC in Iran. Materials and Methods: A total of 104 patients with gastric cancer and 100 controls were recruited. Genomic DNA was extracted from fresh gastric samples. Genotyping of the p53 and MDM2 genes was performed using allele specific PCR (AS-PCR). Results: There was no significant difference between the p53 codon 72 polymorphism distribution in control and patient groups (p=0.54), but the G allele of MDM2 was found to be over-represented in patients (p=0. 01, Odds Ratio=2. 08, 95% Confidence Interval= 1.37-4.34). Conclusions: The p53 R72P seems not to be a potential risk factor for development of GC among Iranian patients, but our data suggest that MDM2 SNP309 might modify the risk related to GC.