Overexpression Of Mutant P53 Protein Research Articles

Galectin-1-mediated expression of proteins-regulators of cell cycle and growth factors in gastric cancer

The purpose of the study was to analyze the expression of proteins-regulators of the cell cycle (p53 and p21) and receptors for endothelial (VEGFR) and epidermal (EGFR) growth factors depending on the expression of galectin-1 in tumor cells in gastric cancer. Materials and methods. 52 patients with diagnosis of gastric cancer were examined. We used the tissue samples of malignant neoplasms of the stomach, which were obtained during surgical intervention. In tumor tissue the expression of galectin-1, p53 and p21 proteins, and receptors of VEGF and EGF were evaluated by immunohistochemistry. The obtained results were analyzed by statistical methods. Results. It is shown that in patients with gastric cancer accompanied by overexpression of galectin-1, high expression of mutant protein p53 and EGFR in tumor tissue was recorded significantly more frequently. Low expression of VEGFR was observed in all patients with gastric cancer regardless of the level of expression of galectin-1 by tumor cells. Association of galectin-1 expression with expression of protein p53 and EGF receptor by stomach tumor cells was set. Conclusion. The relationship between overexpression of galectin-1 and overexpression of mutant p53 protein (not showing antioncogenic properties) and receptor for epidermal growth factor (EGFR) by stomach tumor cells is a negative prognostic criterion of the neoplastic process in gastric cancer.

Abstract 4939: Evaluating a novel biomarkers set for postoperative outcome in patients with gastrointestinal cancer

Abstract Gastrointestinal cancer is the leading cause of cancer deaths in developed countries. The incidence of gastroinetestinal cancer has been increasing dramatically in Japan and has attracted worldwide attention. Despite the introduction of new postoperative chemotherapy regimens and the progress in endoscopic surgery techniques, overall survival is still poor for most advanced gastrointestinal cancer patients. The prognosis of gastrointestinal cancer patients is based on the presence of lymph node metastasis and the depth of tumour cell invasion. Usually, these parameters can be determined by microscopic examination of tissue sections from the primary neoplasm and lymph nodes. However, it is not always possible to establish a prognosis based only on the histopathological examination of cancer specimens. Therefore, there is continuing interest in prognostic factors that can permit more accurate patient stratification, improve clinical decision-making and possibly contribute to more rational study analysis. In the past few years, much progress has been made towards a better understanding of the molecular mechanisms of gastrointestinal cancer. Mutations and overexpression of p53 are common characteristics of various solid tumors. The overexpression of mutant p53 protein has been found to induce the formation of serum p53 IgG antibodies in gastrointestinal cancer patients. In addition, recent studies have revealed that the inflammation-based scoring is a useful tool for predicting postoperative outcome in gastrointestinal cancer patients. Therefore, in this study, we retrospectively reviewed a database of patients who had undergone elective surgery for gastrointestinal cancer at the Division of Surgical Oncology, Nagasaki University Hospital, and that was conducted to evaluate the usefulness of the combination of such biomarkers (CEA, CA19-9, GPS, s-p53ab etc.) for prediction of postoperative mortality in gastroinetestinal cancer patients. Citation Format: Kunizaki Masaki, Shigekazu Hidaka, Tetsurou Tominaga, Yoichi Furukawa, Takeshi Nagayasu. Evaluating a novel biomarkers set for postoperative outcome in patients with gastrointestinal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4939.

Immunohistochemical evaluation of mutant p53 protein over-expression in non-mucinous adenocarcinoma in-situ and invasive adenocarcinoma, NOS of lung

To study the over-expression of mutant p53 protein in non-mucinous adenocarcinoma in-situ (NMAIS) and invasive adenocarcinoma, NOS of lung. Immunohistochemical study for p53 protein was performed on 17 cases of NMAIS and 70 cases of invasive adenocarcinoma, NOS of lung. The difference in p53 over-expression between the two tumor subtypes was analyzed. The over-expression of mutant p53 protein was observed in 0 case (0%) of NMAIS and 37 cases (52.9%) of invasive adenocarcinoma, NOS of lung. The difference was of statistical significance (P = 0.000). Mutant p53 protein over-expression may play a role in the progression of NMAIS to invasive adenocarcinoma, NOS.

Assessment of the potential diagnostic value of serum p53 antibody for cancer: a meta-analysis.

BackgroundMutant p53 protein over-expression has been reported to induce serum antibodies against p53. We assessed the diagnostic precision of serum p53 (s-p53) antibodies for diagnosis of cancer patients and compared the positive rates of the s-p53 antibody in different types of cancers.MethodsWe systematically searched PubMed and Embase, through May 31, 2012. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures using diagnostic odds ratios (DORs) and Area under the curve(AUC). Meta regression and subgroup analyses were done, and heterogeneity and publication bias were assessed.ResultsOf 1089 studies initially identified, 100 eligible studies with 23 different types of tumor met the inclusion criteria for the meta-analysis (cases = 15953, controls = 8694). However, we could conduct independent meta analysis on only 13 of 36 types of tumors. Approximately 56% (56/100) of the included studies were of high quality (QUADAS score≥8). The summary estimates for quantitative analysis of serum p53 antibody in the diagnosis of cancers were: PLR 5.75 (95% CI: 4.60–7.19), NLR 0.81 (95%CI: 0.79–0.83) and DOR 7.56 (95% CI: 6.02–9.50). However, for the 13 types of cancers on which meta-analysis was conducted, the ranges for PLR (2.33–11.05), NLR (0.74–0.97), DOR (2.86–13.80), AUC(0.29–0.81), and positive rate (4.47%–28.36%) indicated significant heterogeneity. We found that breast, colorectal, esophageal, gastric, hepatic, lymphoma, lung and ovarian cancer had relatively reasonable diagnostic accuracy. The remaining results of the five types of cancers suggested that s-p53 antibody had limited value.ConclusionsThe current evidence suggests that s-p53 antibody has potential diagnostic value for cancer, especially for breast, colorectal, esophageal, gastric, hepatic, lymphoma, lung and ovarian cancer. The results showed that s-p53 antibody had high correlation with cancers.

Potential Diagnostic Value of Serum p53 Antibody for Detecting Esophageal Cancer: A Meta-Analysis

BackgroundMutant p53 protein overexpression has been reported to induce serum antibodies against p53. Various studies assessing the diagnostic value of serum p53 antibody in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the potential diagnostic value of serum p53 antibody in esophageal cancer.MethodsWe systematically searched PubMed and Embase until 31st May 2012, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). Positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures diagnostic odds ratio (DOR) and symmetric summary receiver operating characteristic (sROC). The PLR and NLR and their 95% confidence interval (CI) were calculated using a fixed effects model according to the Mantel-Haensed method and random effects model based on the work of Der Simonian and laird, respectively.ResultsFifteen studies (cases = 1079, controls = 2260) met the inclusion criteria for the meta-analysis. Approximately 53.33% (8/15) of the included studies were of high quality (QUADAS score≥8), which were retrospective case-control studies. The summary estimates for quantitative analysis of serum p53 antibody in the diagnosis of esophageal cancer were PLR 6.95 (95% CI: 4.77–9.51), NLR 0.75 (95%CI: 0.72–0.78) and DOR 9.65 (95%CI: 7.04–13.22). However, we found significant heterogeneity between NLRs.ConclusionsThe current evidence suggests serum p53 antibody has a potential diagnostic value for esophageal cancer. However, its discrimination power is not perfect because of low sensitivity.ImpactThese results suggest that s-p53-antibody may be useful for monitoring residual tumor cells and for aiding in the selection of candidates for less invasive treatment procedures because of the high specificity of s-p53-antibody. Further studies may need to identify patterns of multiple biomarkers to further increase the power of EC detection.

Minimal uterine serous carcinoma: a clinicopathological study of 40 cases

The term ‘minimal uterine serous carcinoma’ has been proposed to include serous carcinomas with invasion limited to the endometrium (superficial serous carcinoma), and those without stromal invasion (intraepithelial serous carcinoma or endometrial intraepithelial carcinoma). Both lesions display similar cytological and immunohistochemical profiles of a typical invasive serous carcinoma with a high nuclear grade and an overexpression of mutant p53 protein. We studied the clinicopathologic features of 40 cases of minimal uterine serous carcinoma. All patients were postmenopausal and underwent hysterectomy and surgical staging procedures. There were nine cases of intraepithelial serous carcinoma and 31 cases of superficial serous carcinoma. Five intraepithelial serous carcinomas and 16 superficial serous carcinomas exclusively involved an endometrial polyp. A total of 18 minimal uterine serous carcinomas also involved, in addition to a polyp, the endometrium proper in the form of intraepithelial serous carcinoma (13 cases) and superficial serous carcinoma (five cases). Overall, minimal uterine serous carcinomas were found to involve an endometrial polyp in 88% of the cases (35/40) and were confined to the polyp in 53% (21/40). Extrauterine tumors were present in 45% of the cases (18/40). In all, 22 patients with tumor limited to their uteri demonstrated an overall survival of 94% (2–73 months of follow-up). Eight of 18 patients with extrauterine tumors died of their malignancy (1.5–62 months of follow-up). In conclusion, a significant majority of minimal uterine serous carcinomas involve an endometrial polyp. Complete surgical staging is important to predict the prognosis. When the lesion is confined to an endometrial polyp and/or the endometrium proper, the clinical outcome is excellent.

Establishment of an oral squamous cell carcinoma cell line (NOS-1) exhibiting amplification of the erbB-1 oncogene and point mutation of p53 tumor suppressor gene: its biological characteristics and animal model of local invasion by orthotopic transplantation of the cell line.

We established a new cancer cell line, NOS-1, which was derived from a human oral primary squamous cell carcinoma. Geneticin treatment was adopted to eliminate contaminating fibroblasts and to enrich tumor cells in the early stage of the culture. The NOS-1 cells showed epithelial morphological features with light and electron microscopy, and immunohistochemical analysis confirmed their epithelial origin. Overexpression of mutant p53 protein, a p53 point mutation at codon 248 with transition from CGG to TGG, and amplification of the erbB-1 oncogene/epidermal growth factor receptor gene were also observed in NOS-1 cells. The NOS-1 cells formed tumors in nude mice when transplanted subcutaneously into their backs. Further, they were transplantable orthotopically in the tongues of nude mice, and the transplanted tumors in the tongue showed diffuse invasion without forming capsules. The NOS-1 cells were useful for elucidating the mechanism involving p53 inactivation and erbB-1 oncogene amplification, as well as treatment of oral cancer.

Mutant p53 protein overexpression in women with ipsilateral breast tumor recurrence following lumpectomy and radiation therapy

BACKGROUND The p53 tumor suppressor gene encodes a nuclear phosphoprotein that is thought to be important to cell cycle regulation and DNA repair and that also may regulate induction of apoptosis by ionizing radiation. Somatic p53 gene mutations occur in 30–50% of breast carcinomas and are associated with poor prognosis. Mutations in the p53 gene result in prolonged stability of the protein that can be detected by immunohistochemical techniques. In a matched case–control study of breast carcinoma patients with ipsilateral breast tumor recurrence (IBTR) following lumpectomy and radiation therapy, the authors investigated the frequency and prognostic significance of somatic p53 mutations as well as the clinical characteristics of patients with these mutations. METHODS Between 1973 and 1995, there were 121 breast carcinoma patients with IBTR following lumpectomy and radiation therapy, and the authors identified 47 patients in whom the paraffin embedded tissue blocks from the primary breast tumors were available for further molecular analysis. Forty-seven control breast carcinoma patients from the breast carcinoma data base were individually matched to the index cases who did not have IBTR for age, treatment date, follow-up, histology, margin status, radiation dose, and adjuvant treatment. Immunohistochemistry using a monoclonal antibody to mutant p53 protein was used to determine mutant p53 protein overexpression in breast tumors and appropriately scored. RESULTS A total of 12 of 47 tumor specimens (26%) from index patients with breast tumor relapses demonstrated mutant p53 protein overexpression, whereas only 4 of 47 specimens from controls (9%) demonstrated high mutant p53 immunoreactivity (P = 0.02). The authors found that 9 of 23 patients (39%) with early breast tumor recurrences (recurrences within 4 years of diagnosis) had overexpression of mutant p53 protein, whereas only 1 of 23 control cases (4%) had high mutant p53 protein immunoreactivity (P = 0.003). In contrast, index cases from patients with late breast tumor relapses (more than 4 years after diagnosis), which are more likely to represent de novo breast tumors, and control cases from the breast carcinoma data base without IBTR had similar levels of mutant p53 protein overexpression (P = not significant). The 10-year distant disease free survival for patients with mutant p53 protein was 48%, compared with 67% for breast carcinoma patients without detection of mutant p53 protein (P = 0.08). The authors found that 13 of 14 primary breast tumors (93%) with mutant p53 protein overexpression were estrogen receptor negative (P = 0.01) and 11 of 14 (79%) were progesterone receptor negative (P = not significant). CONCLUSIONS In a matched case–control study, overexpression of mutant p53 protein has prognostic significance with respect to IBTR following lumpectomy and radiation therapy. Breast tumors with p53 mutations are generally estrogen receptor negative and are associated with compromised distant disease free survival. Cancer 2000;88:1091–8. © 2000 American Cancer Society.

Mutant p53 protein overexpression in women with ipsilateral breast tumor recurrence following lumpectomy and radiation therapy

The p53 tumor suppressor gene encodes a nuclear phosphoprotein that is thought to be important to cell cycle regulation and DNA repair and that also may regulate induction of apoptosis by ionizing radiation. Somatic p53 gene mutations occur in 30-50% of breast carcinomas and are associated with poor prognosis. Mutations in the p53 gene result in prolonged stability of the protein that can be detected by immunohistochemical techniques. In a matched case-control study of breast carcinoma patients with ipsilateral breast tumor recurrence (IBTR) following lumpectomy and radiation therapy, the authors investigated the frequency and prognostic significance of somatic p53 mutations as well as the clinical characteristics of patients with these mutations. Between 1973 and 1995, there were 121 breast carcinoma patients with IBTR following lumpectomy and radiation therapy, and the authors identified 47 patients in whom the paraffin embedded tissue blocks from the primary breast tumors were available for further molecular analysis. Forty-seven control breast carcinoma patients from the breast carcinoma data base were individually matched to the index cases who did not have IBTR for age, treatment date, follow-up, histology, margin status, radiation dose, and adjuvant treatment. Immunohistochemistry using a monoclonal antibody to mutant p53 protein was used to determine mutant p53 protein overexpression in breast tumors and appropriately scored. A total of 12 of 47 tumor specimens (26%) from index patients with breast tumor relapses demonstrated mutant p53 protein overexpression, whereas only 4 of 47 specimens from controls (9%) demonstrated high mutant p53 immunoreactivity (P = 0.02). The authors found that 9 of 23 patients (39%) with early breast tumor recurrences (recurrences within 4 years of diagnosis) had overexpression of mutant p53 protein, whereas only 1 of 23 control cases (4%) had high mutant p53 protein immunoreactivity (P = 0.003). In contrast, index cases from patients with late breast tumor relapses (more than 4 years after diagnosis), which are more likely to represent de novo breast tumors, and control cases from the breast carcinoma data base without IBTR had similar levels of mutant p53 protein overexpression (P = not significant). The 10-year distant disease free survival for patients with mutant p53 protein was 48%, compared with 67% for breast carcinoma patients without detection of mutant p53 protein (P = 0. 08). The authors found that 13 of 14 primary breast tumors (93%) with mutant p53 protein overexpression were estrogen receptor negative (P = 0.01) and 11 of 14 (79%) were progesterone receptor negative (P = not significant). In a matched case-control study, overexpression of mutant p53 protein has prognostic significance with respect to IBTR following lumpectomy and radiation therapy. Breast tumors with p53 mutations are generally estrogen receptor negative and are associated with compromised distant disease free survival.

P53-Regulated Apoptosis Is Differentiation Dependent in Ultraviolet B-Irradiated Mouse Keratinocytes

Previous studies from our laboratory, using p53 transgenic mice, have suggested that ultraviolet (UV) light-induced keratinocyte apoptosis in the skin is not affected by overexpression of mutant p53 protein. To further elucidate a possible role for p53 in UV-induced keratinocyte cell death, we now examine apoptosis in skin and isolated keratinocytes from p53 null (-/-) mice and assess the influence of cell differentiation on this process. In vivo, using this knockout model, epidermal keratinocytes in p53-/- mice exhibited only a 5.2-fold increase in apoptosis after 2000 J/m2 UVB irradiation compared with a 26.3-fold increase in normal control animals. If this p53-dependent apoptosis is important in elimination of precancerous, UV-damaged keratinocytes, then it should be active in the undifferentiated cells of the epidermal basal layer. To test this hypothesis, we examined the effect of differentiation on UV-induced apoptosis in primary cultures of murine and human keratinocytes. Apoptosis was p53-independent in undifferentiated murine keratinocytes, which exhibited relative resistance to UVB-induced killing with only a 1.5-fold increase in apoptosis in p53+/+ cells and a 1.4-fold increase in p53-/- cells. Differentiated keratinocytes, in contrast, showed a 9.4-fold UVB induction of apoptosis in p53+/+ cells, almost three times the induction observed in p53-/- cells. This UV-induced difference in apoptosis was observed when keratinocytes were cultured on type IV collagen substrate, but not on plastic alone. Western blotting of UV-irradiated, differentiated keratinocytes did not support a role for either Bax or Bcl-2 in this process. In support of these findings in mice, cell death in human cultured keratinocytes also occurred in a differentiation-associated fashion. We conclude that p53-induced apoptosis eliminates damaged keratinocytes in the differentiated cell compartment, but this mechanism is not active in the basal, undifferentiated cells and is therefore of questionable significance in protection against skin cancer induction.

Implications of p53 alterations and anti-p53 antibody response in head and neck squamous cell carcinomas.

Point mutations at the tumour suppressor gene p53 are one of the most frequent genetic alterations in squamous cell carcinoma of the head and neck (SCCHN), which lead to the nuclear accumulation and overexpression of inactive p53 protein. The overexpression of mutant p53 protein can induce a specific humoral response in cancer patients. p53 protein was studied in 112 SCCHN. Biopsies and sera samples were collected before initiation of treatment. 74 patients received neoadjuvant chemotherapy (5-fluorouracil-cisplatin-folinic acid). p53 protein expression was evaluated by immunohistochemistry (IHC) on paraffin-embedded sections. The analysis of mutations was assessed by PCR-SSCP of exons 5-10 on DNA from 28 representative cases. Antibodies specific for p53 protein were analysed in sera of 74 patients by an ELISA procedure. Overexpression (> 20% positive cells) of p53 protein was frequent (56%: 63/112) and was correlated with localisation of the primary tumour and tumour stage. p53 mutations were detected in 57% (16/28) of studied cases. The prevalence of p53 antibodies in sera was high (44% 32/74) and among this population, 68% (20/29) had a positive immunophenotype and 67% (6/9) a p53 mutation in the tumour. In addition, the presence of anti-p53 antibodies was slightly associated with complete response to neoadjuvant chemotherapy. If the humoral response seems to be an indicator of the p53 protein status, the detection of anti-p53 antibodies could be a good approach in the early detection of the presence of p53 alterations in SCCHN and recurrent tumours or the appearance of second primary cancer.

Human ovarian cancer of the surface epithelium

Epidemiologic studies have shown that the risk of cancer in the ovarian surface epithelium is decreased by factors that suppress ovulation, whereas uninterrupted ovulation has been associated with increased risk. This suggests that ovulation may play a critical role in ovarian carcinogenesis. More recently, molecular studies have demonstrated alterations in specific oncogenes and tumor suppressor genes in ovarian cancers. Overexpression of the HER-2/ neu oncogene occurs in approximately 30% of ovarian cancers and correlates with poor survival. Although mutation of the K- ras oncogene has been found in some mucinous ovarian cancers, mutations in this gene appear to be more common in borderline ovarian tumors. Amplification of c- myc occurs in approximately 30% of ovarian cancers and is more frequently seen in serous cancers. Mutation of the p53 tumor suppressor gene, with resultant overexpression of mutant p53 protein, occurs in 50% of stage III/IV and 15% of stage 1/11 ovarian cancers. Most p53 mutations in ovarian cancers are transitions, which suggests that they arise spontaneously rather than due to exogenous carcinogens. In contrast to the acquired genetic alterations described above that are a feature of sporadic ovarian cancers, 5–10% of ovarian cancers probably arise due to inherited genetic defects. Recently, the BRCA1 tumor suppressor gene has been identified and shown to be responsible for most cases of hereditary ovarian cancer. Further studies are needed to augment our understanding of the molecular pathogenesis of ovarian cancer.

Racial disparity in overexpression of the p53 tumor suppressor gene in stage I endometrial cancer

OBJECTIVE: This study was conducted to determine whether overexpression of the p53 tumor suppressor gene is associated with poor outcome in early-stage endometrial cancers and whether a racial difference in the frequency of p53 overexpression contributes to the observed racial disparity in survival rates. STUDY DESIGN: Immunostaining for the p53 gene was performed in 164 women with stage I endometrial adenocarcinomas. RESULTS: Overexpression of mutant p53 protein was seen in 28 out of 164 (17%) cases and was associated with a poor histologic grade ( p = 0.003) and a nonendometrioid histologic appearance ( p = 0.06). Overexpression also was three times more frequent in blacks (15 out of 44, 34%) than in whites (13 out of 117, 11%) ( p = 0.003). Recurrent disease developed in 15 out of 164 (9%) cases and was more than twice as frequent in cases when the p53 gene was overexpressed (5 out of 28, 18%) than in cases with normal expression (10 out of 136, 7%). Recurrent disease was seen in 6 out of 44 (14%) blacks compared to 9 out of 117 (8%) whites. CONCLUSIONS: These data support the hypothesis that differences in the frequency of alteration of the p53 tumor suppressor gene contribute to the racial disparity in endometrial cancer survival. (Am J Obstet Gynecol 1997;176:S229-32.)

Coabnormal expression of cyclin D1 and p53 protein in human uterine endometrial carcinomas.

In the normal cell cycle, tumor suppressor gene products (p53) and cyclin (cyclin D1) cooperate. Abnormalities in the cooperation of these factors may result in malignant transformation of the cell. Mutant p53 protein overexpression is defined in many human cancers, including endometrial carcinoma. This study investigated the role of cyclin D1 in the development of human uterine endometrial carcinoma. Seventy-four patients whose pathology slides contained either normal or hyperplastic endometrium adjacent to endometrial carcinoma were studied. Immunohistochemical staining of the serial paraffin sections was performed using antibodies to p53 and cyclin D1. The expression of cyclin D1 was restricted to only a few cells of normal and hyperplastic endometrium, whereas it was preferentially expressed in 40% (30/74) of endometrial carcinomas. The cells that overexpressed cyclin D1 also overexpressed p53. Moreover, all 30 cases with varied distributions of cyclin D1-positive cells corresponded identically with the distribution of p53-positive cells. Diffuse positivity for cyclin D1 was specifically observed in clinically advanced stages of pathologic G2 and G3 tumors. The data suggest that coabnormal expression of cyclin D1 and p53 protein may contribute to the development of endometrial carcinoma and may also be involved in the progression to malignancy.

Coabnormal expression of cyclin D1 and p53 protein in human uterine endometrial carcinomas

BACKGROUND In the normal cell cycle, tumor suppressor gene products (p53) and cyclin (cyclin D1) cooperate. Abnormalities in the cooperation of these factors may result in malignant transformation of the cell. Mutant p53 protein overexpression is defined in many human cancers, including endometrial carcinoma. This study investigated the role of cyclin D1 in the development of human uterine endometrial carcinoma. METHODS Seventy-four patients whose pathology slides contained either normal or hyperplastic endometrium adjacent to endometrial carcinoma were studied. Immunohistochemical staining of the serial paraffin sections was performed using antibodies to p53 and cyclin D1. RESULTS The expression of cyclin D1 was restricted to only a few cells of normal and hyperplastic endometrium, whereas it was preferentially expressed in 40% (30/74) of endometrial carcinomas. The cells that overexpressed cyclin D1 also overexpressed p53. Moreover, all 30 cases with varied distributions of cyclin D1-positive cells corresponded identically with the distribution of p53-positive cells. Diffuse positivity for cyclin D1 was specifically observed in clinically advanced stages of pathologic G2 and G3 tumors. CONCLUSIONS The data suggest that coabnormal expression of cyclin D1 and p53 protein may contribute to the development of endometrial carcinoma and may also be involved in the progression to malignancy. Cancer 1996;78:1248-53.

C-erbB-2, p53, N-ras expression in hepatocellular carcinoma

To assess the relationship between C-erbB-2, p53, N-ras status at a premalignant stage and in HCC, the authors studied the imunohistological expression of these genes in HCC, liver cirrhosis and in the adjacent normal resected liver tissue, using monoclonal antibody to mutated p53 and activated C-erbB-2, N-ras. C-erbB-2 was expressed in 97.1% (35/36) of HCC and 100% (18/18) of hepatic cirrhosis, low level C-erbB-2 expression was observed in 2/14 (14.3%) of normal liver specimens; The positive incidence of overexpression of mutant p53 protein in HCC and hepatic cirrhosis were 55.6% (20/36) and 66.7% (10/18) respectively; 29 (76.5%) specimens of HCC and 16 (88.9%) of hepatic cirrhosis were positive for N-ras protein. The overexpression of the three oncogene proteins were significantly higher than that of normal liver tissues (P<0.01). These results indicated that activated C-erbB-2, N-ras and altered p53 genes may have a role in human HCC pathogenesis through promiting the development of HCC from hepatic cirrhosis and the progression of HCC.

Molecular basis of endometrial cancer

Most human cancers are thought to arise from alterations in oncogenes and tumor suppressor genes. Molecular techniques have been used to identify specific genetic alterations in endometrial cancers. Overexpression of the HER-2/neu oncogene occurs in 10% of endometrial cancers and correlates with poor survival. Alterations in other receptor tyrosine kinases (c-fms and epidermal growth factor receptor) also occur in some cases. The c-myc oncogene, which encodes a nuclear transcription factor, also may be overexpressed in some invasive cancers. Mutations in the K-ras oncogene occur in 10% and in 20-30% of American and Japanese endometrial cancers, respectively. K-ras mutations also have been observed in endometrial hyperplasias, and this may represent an early event in the development of some cancers. Mutation of the p53 tumor suppressor gene, with resultant overexpression of mutant p53 protein, occurs in 20% of endometrial adenocarcinomas. Overexpression of p53 is associated with advanced stage and poor survival. Because p53 mutations do not occur frequently in endometrial hyperplasias, this may be a relatively late event in endometrial carcinogenesis. Recent studies have shown that mutations occur in microsatellite sequences in some endometrial cancers. Because microsatellite instability in hereditary nonpolyposis colon cancer has been found to be caused by mutations in DNA repair genes, similar mutations are being sought in endometrial cancers. Although several molecular alterations have been identified, the molecular pathogenesis of endometrial cancer remains poorly understood.

Serum p53 antibodies as early markers of lung cancer.

The p53 alteration is the most common alteration found in human cancer. It usually involves missense mutations that stabilize the p53 protein, which in turn accumulates, reaching levels detectable by immunohistochemistry. We and others have demonstrated that this overexpression of mutant p53 protein can induce a specific humoral response in cancer patients. This result was assessed by the presence of p53 antibodies in sera of patients with various types of cancers, whereas normal populations do not exhibit such antibodies. In lung cancer, the prevalence of p53 antibodies is high (30%) and is correlated with a very high rate of p53 mutations in this cancer (60-70%). We show that these antibodies are always present at the time of diagnosis, but never appear during tumour development, an observation strengthened by the fact that these antibodies are mostly IgG, corresponding to a secondary immune response. These results suggest that the humoral response is an early event and that p53 antibodies can be used as a precocious marker of p53 alteration before clinical manifestation of the disease.

Relationships between mutant P53 protein overexpression and other prognostic indicators in breast cancer

Relationships between mutant P53 protein overexpression and other prognostic indicators in breast cancer

Mutant p53 in Patients with Invasive Cervical Cancer Stages IB to IIB

The present study evaluates the prognostic value of mutant p53 protein overexpression in 109 surgically treated cervical cancer stages IB to IIB. Squamous cell carcinoma stages IB, IIA, and IIB were present in 52, 13, and 44 cases, respectively. We performed immunohistochemistry using a monoclonal antibody against the p53 suppressor gene product (clone BP53-12). Data were analyzed for the end points of disease-free survival and overall survival. In 109 tissue specimens we detected 22 cases of p53 expression. Six of 22 patients with p53 expression and 21 of 87 patients without p53 expression showed tumor recurrences. p53 expression showed no significant correlation to age, tumor stage or lymph node involvement. In the univariate analysis p53 expression showed no prognostic value for disease-free (P = 0.5) and overall survival (P = 0.6). Multivariate analysis showed a significant prognostic value for established prognostic parameters while p53 expression had no prognostic value for recurrence-free (P = 0.6) and overall survival (P = 0.5). In contrast to other malignancies mutant p53 overexpression showed no relation to prognosis in surgically treated cervical cancer stage IB to IIB.