Immunohistochemical analysis of p53 protein overexpression in normal, premalignant, and malignant tissues of the cervix uteri

Diagnostic Algorithmic Proposal Based on Comprehensive Immunohistochemical Evaluation of 297 Invasive Endocervical Adenocarcinomas

The International Endocervical Adenocarcinoma Criteria and Classification was developed to separate endocervical adenocarcinomas (ECAs) into 2 main categories on the basis of morphology such as human papilloma virus-associated (HPVA) and non-human papilloma virus-associated adenocarcinomas. We aimed to improve the diagnostic accuracy of International Endocervical Adenocarcinoma Criteria and Classification by performing a comprehensive immunohistochemical evaluation and constructing objective immunohistochemical-based algorithms for the classification of these tumors. Tissue microarrays were constructed from 297 of 409 cases used to develop the original classification. Immunostains included p16, p53, estrogen receptor (ER), progesterone receptor, androgen receptor, Vimentin, CK7, CK20, HER2, HIK1083, MUC6, CA-IX, SATB2, HNF-1beta, napsin A, PAX8, CDX2, GATA3, p63, p40, and TTF-1. High-risk human papilloma virus (HR-HPV) was detected by in situ hybridization (ISH) using probes against E6 and E7 mRNA expressed in 18 different virus types. Vimentin, ER, and progesterone receptor were expressed in a significant minority of ECAs, mostly HPVAs, limiting their use in differential diagnosis of endometrioid carcinoma when unaccompanied by HPV-ISH or p16. HR-HPV ISH had superior sensitivity, specificity, and negative and positive predictive values compared with p16, as published previously. HNF-1beta did not have the anticipated discriminatory power for clear cell carcinoma, nor did MUC6 or CA-IX for gastric-type carcinoma. HNF-1beta and napsin A were variably expressed in clear cell carcinoma, with HNF-1beta demonstrating less specificity, as it was ubiquitously expressed in gastric-type carcinoma and in the majority of HPV-associated mucinous (predominantly intestinal-type and invasive ECA resembling stratified mucin-producing intraepithelial lesion [iSMILE]) and usual-type carcinomas. HIK1083 was expressed in nearly half of gastric-type carcinomas, but not in the vast majority of other subtypes. GATA3 was positive in 10% of usual-type adenocarcinomas and in single examples of other subtypes. Rare gastric-type and HPVA mucinous carcinomas displayed HER2 overexpression. Androgen receptor was positive in 6% of usual-type adenocarcinomas. Aberrant p53 expression was found in only 3.6% of usual-type HPVA carcinomas, but it was more prevalent in mucinous (intestinal type and iSMILE) HPVAs and non-human papilloma virus-associates (particularly in gastric-type carcinoma, >50% of cases). The following diagnostic classification algorithms were developed with the above data. Carcinomas without overt cytoplasmic mucin (endometrioid, usual-type endocervical, clear cell, and mesonephric carcinomas) can be subclassified using HR-HPV ISH, ER, and GATA3, whereas carcinomas with easily appreciated cytoplasmic mucin (endometrioid carcinoma with mucinous features, HPVA mucinous, and gastric-type carcinomas) can be subclassified with HR-HPV ISH and ER.

The Role of p53 Gene in Cervical Carcinogenesis

AIM

To investigate the role of p53 gene in cervical carcinogenesis.

MATERIALS AND METHODS

A total 50 cases and controls were taken after setting exclusion criteria. Venous blood (3 ml) samples were collected in sterile EDTA sterile vials. Both punch biopsy of cervical growth in cases and biopsy from cervix after hysterectomy in controls were performed. Genomic DNA was extracted from tissue and blood using standard protocol of Miller et al. 1994 using chloroform-phenol method. Gene was amplified using specific forward and reverse primers and p53 gene expressions were studied. The present study of p53 gene regulation analyzed the expression of 279-bp bands on 1.5 agarose gel.

OBSERVATIONS

Out of the total 50 samples of cases and controls, we were able to isolate DNA from 38 cases and 28 controls in blood and in 22 cases and 22 controls in tissue. In cases of carcinoma cervix, p53 expression is either downregulated or absent in 71.06 % of cases compared to 50 % of controls in blood and 72.73 % of cases compared to 59.09 % of controls in tissue, but these figures were not statistically significant (p = 0.67 and p = 0.167, respectively). p53 positivity rate was only in 27.78 % of squamous cell cancer and 50 % of adenocarcinoma. Three out of nine patients (33.3 %) with L.N. positive status have p53 gene positivity, whereas 23 % (3 out of 13) with L.N. negative status have p53 gene positivity, which is not significantly associated. In our study, p53 overexpression increases with the various stages of cervical cancer.

CONCLUSION

In our study, we found that there is the increased frequency of upregulation or overexpression of p53 gene in control in both blood (50 %) and tissue (40.9 %), but this association is statistically nonsignificant. In the present study, there is a lack of relationship between p53 overexpression and prognosis in the cervical cancer patients. However, our study lacked larger sample size which otherwise would have been able to lend support to truly significant findings through much larger combined and comparative datasets.

Histopathology and Prognostic Indices of Carcinoma Breast with Special Reference to p53 Marker

INTRODUCTION

Cancer of the breast is one of the commonest carcinomas in women, both in western world and in India. The high frequency of breast cancer in women has prompted an intensive study of possible modifiable risk factors (clinical parameters, morphological typing, and biological markers) for assessment of prognosis, prevention strategies, and treatment modalities. p53 is one of the most significant prognostic markers for breast carcinomas.

AIMS AND OBJECTIVES

This study was undertaken to ascertain the prevalence of p53 mutated protein in breast carcinomas by immunohistochemistry and correlating the results with clinical and histological parameters and also determine its influence on axillary node metastasis.

MATERIALS AND METHODS

Clinico-pathological evaluation of 50 cases of infiltrating ductal carcinoma of the breast, with reference to p53 mutated protein expression by means of immunohistochemistry was undertaken.

RESULTS

The percentage positivity of p53 immunohistochemistry of this study was 22% which is similar to the reported statistics of various other studies. The immunohistochemistry results also showed an equivocal p53 status in both the positive and negative cases of lymph node metastases. The carcinomas with p53 positivity demonstrated aggressive characteristics, including larger size, higher grade, in comparison with p53 negative cases. The probability of getting positive p53 status was higher for those with severe lymphocytic reaction of tumours, for patients less than 35 years of age and for those with tumour on the left side. This study clearly indicates that p53 over expression in breast cancers are mostly aggressive tumours and they confer poor prognosis and likelihood of a poor response to endocrine therapy and chemotherapy.

Immunohistochemical Expression of Cell Proliferating Nuclear Antigen (PCNA) and p53 Protein in Cervical Cancer

OBJECTIVE

This study was designed to evaluate the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) and p53 protein expression in preneoplastic and neoplastic lesions in uterine cervix.

STUDY DESIGN

A total of 36 cervical biopsies were subjected for immunostaining and the results were correlated with different prognostic parameters. Bivariate and multivariate statistical analyses were done using "STATA" software.

RESULTS

PCNA labeling index and p53 expression increased with increasing severity of CIN lesions. PCNA labeling index was maximum (46.0) carcinoma cervix with intense positive staining. In bivariate statistical analysis, p53 and PCNALI were found to be insignificant (0.4184 and 0.4328, respectively). Menopausal stage was significantly associated with CA and CIN groups (P < 0.166 and P < 0.049), respectively.

CONCLUSION

These markers may be of greater importance in low-grade CIN lesions showing high proliferative index. This will place the low-grade lesions in higher grade indicating the utility of proliferative markers in decision making for intervention. This method is simple and cost effective and may be useful in developing countries where HPVDNA testing is still out of reach because of high cost.

Neoplastic Lesions of the Cervix

This review presents a discussion of the gross and microscopic features, diagnosis, differential diagnosis, and prognosis of neoplastic lesions of the cervix. Biomarkers are discussed for each entity presented - cervical intraepithelial neoplasia, squamous carcinoma, glandular neoplasms, adenocarcinoma in situ, adenosquamous carcinoma, and others.

Losses of expression of the antigens A, Lea and Lex and over-expression of Ley in carcinomas and HG-SIL of the uterine cervix

BACKGROUND

The glycosylation of a great number of molecules, glyco-protein or glycolipids, has been of interest for decades.

OBJECTIVE

To compare the expressive patterns of the isoantigenic determinants of histo-blood groups ABH and Lewis in squamous and simple epithelium and in precursors and cancers of the cervix.

METHODS

A total of 36 lesions and neoplasms (10 LG-SIL, 16 HG-SIL and 10 invasive carcinomas) have been studied with immunohistochemical techniques, using monoclonal antibodies (MoAb BG1 to BG8) for precursor chains, blood-group ABH and Lewis group Le(a), Le(b), Le(x), and Le(y), and four types of lectins. In addition, we have studied the expression of p53 protein and PCNA, establishing the rate of proliferation of each lesion. Using PCR techniques, we have also detected part of the intron of the E6 gene of HPV-16.

RESULTS

In the invasive cervical carcinomas, we observed a loss of expression of the Le(x) antigen (p < 0.01). With regard to the progression of the different lesions studied, we found alterations in the patterns of expression of the antigens of the ABH and Lewis blood groups. There was a tendency towards a loss of expression and heterogeneous patterns in the more advanced lesions, as well as over-expression of the Le(y) antigens. With PCNA, we established a proliferative rate which tended to be greater in relation to the progression of the cervix neoplasms.

CONCLUSION

These results indicate that there is a relation between the losses of histo-blood groups and the progression of the squamous intraepithelial lesions.

Serum p53 antibody as a predictor of early recurrence in patients with postoperative esophageal squamous cell carcinoma

It is reported that surveillance of serum p53 antibody (Ab) is a useful marker in detecting esophageal squamous cell carcinoma (ESCC). But there is little reported about prognostic significance of serum p53-Ab in postoperative patients with ESCC. The aim of this study is to evaluate the significance of preoperative serum p53-Ab as a marker of early recurrence after curative resection for ESCC. Enzyme-linked immunosorvent assay (ELISA) was used to analyze serum p53-Ab before treatment in 44 patients with ESCC. Carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC-Ag) were examined by immunoradiometric assay. The patients who were strongly positive and positive in serum p53-Ab were more likely to have early recurrence after curative resection than seronegative patients. There were no significant correlations between CEA, SCC-Ag positivity and early recurrence. We found that serum p53-Ab was useful to predict a risk of early recurrence after curative surgical resection for ESCC.

Correlation p53 expression and human papilloma virus deoxyribonucleic acid with clinical outcome in early uterine cervical carcinoma

BACKGROUND

In the present study we assessed whether expression of p53 protein or HPV DNA correlates with recurrence as well as several known prognostic factors in uterine cervical carcinoma.

METHODS

Forty-nine patients with FIGO stage IA-IIB who underwent hysterectomy between 1998 and 2002 were retrospectively studied. All 49 cancer tissue samples were used for immunohistochemical study. Twenty-five of 49 cases were also examined by PCR-RFLP for detection and typing of HPV DNA.

RESULTS

Twenty of 49 (40.8%) specimens demonstrated nuclear staining for p53. A significant association between p53 overexpression and age, hormonal status, FIGO stage, or recurrence was observed (p=0.02, 0.01, 0.03, 0.01). However, no significant association was found between p53 overexpression and lymph node metastases, parametrium involvement, or risk of death (p=0.18, 0.06, 0.14). Nineteen of 25 (76%) were HPV DNA-positive and 6 (24%) were negative.

DISCUSSION

There was no relation between HPV DNA positivity and age, FIGO stage, lymph node metastases, parametrium involvement, recurrence, or risk of death.

CONCLUSION

p53 overexpression is associated with age, hormonal status, FIGO stage, and recurrence in uterine cervical carcinoma.

Characterization of human papillomavirus infection, P53 and Ki-67 expression in cervix cancer of Mozambican women

In this study, we aimed at evaluating the distribution of HPV types and the expression of P53 and Ki-67 in cervix carcinomas of Mozambican women. Fourty-seven invasive carcinomas, 10 CIN III, and 10 normal cervix were studied. P53 and Ki-67 expression was examined immunohistochemically. HPV infection and HPV types were detected by PCR (GP5+/bio-GP6+) and enzyme-immunoassay, respectively. Expression of P53 and Ki-67 and detection of HPV were as follows: normal cervix--0%, 10%, and 0%, respectively; CIN III--10%, 0%, and 100%, respectively; invasive carcinomas--50%, 55.5%, and 70%, respectively. HPV 16 was identified in 54% of invasive carcinomas, HPV 31, 33, 35, and 45 in 23%, "unidentified" HPV in 19%, and HPV 18 in 4% of invasive carcinomas. No significant associations were observed between P53 expression, Ki-67 expression, and HPV infection. In conclusion, we observed a high frequency of HPV infection in CIN III lesions and invasive carcinomas from Mozambican women, with HPV 16 representing the most frequent viral type. HPV status was not related to P53 and Ki-67 expression. Both P53 and Ki-67 are associated with invasive cervix carcinomas, mainly of the squamous keratinizing histotype.

p53 and p21 expression in precancerous lesions and carcinomas of the uterine cervix: overexpression of p53 predicts poor disease outcome

OBJECTIVES

Abnormal expression of the p53 and p21(waf1/cip1) tumor suppressor genes has been observed in a variety of human tumors, but little is known about its expression during cervical tumorigenesis. To identify the potential implications of both genes in the development of cervical carcinoma and explore the clinical importance of changes in gene expression, we assessed the levels of both proteins in precancerous lesions and carcinomas of the cervix.

METHODS

In our study, 10 low-grade squamous intraepithelial lesions (LSIL), 35 high-grade squamous intraepithelial lesions (HSIL), 12 microinvasive carcinomas, and 103 invasive carcinomas were evaluated. The expression of p53 and p21 was studied by immunohistochemistry using monoclonal antibodies specific for these proteins.

RESULTS

p21 was expressed in all samples of normal epithelium, LSIL, and HSIL, and the mean values of expression were 50.3, 42.5, and 44.5%, respectively. Conversely, the expression of p21 was significantly reduced in microinvasive (30.7%) and invasive carcinomas (9.9%). p53 nuclear staining was not detected in normal epithelium samples or LSILs, while 4 (11.4%) of 35 HSILs, 1 (8.3%) of 12 microinvasive carcinomas, and 38 (36.9%) of 103 invasive carcinomas were positive for p53. Compared with the results of the control group, precancerous lesions, and microinvasive carcinoma, the mean value of p53 expression (4.8%) in invasive carcinoma was significantly higher. Furthermore, p53 overexpression was significantly associated with advanced stage of the tumor (P < 0.001) [16/67 (23.9%) stage I, 15/28 (53.6%) stage II, and 7/8 (87.5%) stage III/IV]. In univariate analysis, p53 overexpression was a significant predictor of poor survival, whereas it had no independent influence on overall survival using the Cox regression method. Our data also revealed that no association between p53 immunostaining and p21 expression was found.

CONCLUSIONS

The trend of reduced p21 expression in microinvasive and invasive carcinomas suggests that p21 may play a tumor-suppressor function in neoplastic transformation in cervical epithelium and inactivation of p21 may be an early event in cervical carcinogenesis. Our results indicated that p53 overexpression was a significant predictor of poor disease outcome in univariate analysis. Moreover, significantly increased expression of p53 in advanced-stage cervical carcinoma implies that inactivation of p53 is associated with tumor progression. Finally, this study further supports the notion that induction of p21 expression can be regulated in a p53-independent manner.

Cell cycle aberrations in the pathogenesis of squamous cell carcinoma of the uterine cervix

Cancer cells are characterized by limitless proliferative autonomy and immunity to inhibitory and apoptotic signals, thus ensuring growth and metastasis [1]. Epidemiological studies have long implicated human papillomavirus (HPV) as a pathogenic agent in cervical cancer. Progress in cancer research now provides an understanding of how these characteristics are achieved by the interaction of HPV proteins with the cell cycle machinery. Expression of oncoproteins E7 and E6 induces immortalization of cells through their inhibitory effects on tumor suppressor proteins pRb and p53, respectively. Undermining of pRb's growth-inhibitory role with release of E2F transcription factors renders the cells independent of mitogenic stimuli. The abundance of growth transcription factors grants limitless proliferative potential by allowing expression of products such as cyclins A, E, and B, dihydrofolate reductase, and DNA polymerase which fuel the various stages of the cell cycle. There is subsequent disruption of both the G1-S and G2-M cell cycle checkpoints. Overexpression of cyclin E results in chromosomal instability and possible unmasking of genetic mutations, allowing disease progression. Cyclin A grants anchorage-independent growth, facilitating tissue invasion and tumor spread. Apoptotic and growth-inhibitory mechanisms are also evaded. p53 is degraded by E6 and its own downstream protein mdm2. Its other downstream protein, p21 is rendered ineffective against cyclin-cyclin-dependent kinase units by E7, as is p27. The understanding of the molecular pathology of disease will provide us with the ability to prognosticate and treat patients more effectively.

Surrogate endpoint biomarkers and their modulation in cervical chemoprevention trials

BACKGROUND

Surrogate endpoint biomarkers (SEBs) are used as intermediate indicators of a reduction in cancer incidence in chemoprevention studies. SEBs should be expressed differentially in normal and high risk tissue; appear at a well defined stage of carcinogenesis; be studied with reasonable sensitivity, specificity, and accuracy; and be modulated in chemoprevention trials. The concept of SEBs may be useful in the trials of many new therapies.

METHODS

The current review includes a comprehensive review of the literature. Many SEBs have been the subject of intense study and include quantitative histopathology and cytology, proliferation markers, regulation markers, differentiation markers, general genomic instability markers, and tissue maintenance markers. Because of the critical biologic and epidemiologic role of the human papillomavirus (HPV) in cervical carcinogenesis, the relation between these markers and HPV should be considered. In addition, biomarkers of HPV infection and its regression should be sought.

RESULTS

Several chemoprevention trials have been published that have included the use of SEBs. The biomarkers that appear most promising in these clinical trials can be measured quantitatively and reproducibly: quantitative histology and cytology, proliferating cell nuclear antigen (PCNA), MIB-1, MPM-2, HPV viral load, epidermal growth factor receptor, polyamines, and ploidy. The markers that have been demonstrated to be modulated in chemoprevention trials in the literature are quantitative histology and cytology, PCNA, MPM-2, HPV viral load, and polyamines.

CONCLUSIONS

The surrogate endpoint biomarkers of most interest in future research should correlate well with HPV infection, be modulated by several therapeutic agents, and have limited variability and ease in measurement.

AgarCyto: a novel cell-processing method for multiple molecular diagnostic analyses of the uterine cervix

In diagnostic cytology, it has been advocated that molecular techniques will improve cytopathological diagnosis and may predict clinical course. Ancillary molecular techniques, however, can be applied only if a sufficient number of preparations are made from a single cell sample. We have developed the AgarCyto cell block procedure for multiple molecular diagnostic analyses on a single scraping from the uterine cervix. The optimized protocol includes primary fixation and transport in ethanol/carbowax, secondary fixation in Unifix, and embedding in 2% agarose and then in paraffin according to a standard protocol for biopsies. More than 20 microscopic specimens were produced from a single AgarCyto cell block, and standard laboratory protocols have been successfully applied for H&E staining, immunohistochemistry for Ki-67 and p53, and in situ hybridization for the centromere of human chromosome 1 and human papilloma virus Type 16. In addition, single AgarCyto sections yielded sufficient input DNA for specific HPV detection and typing by LiPA-PCR, and the protocol includes an option for DNA image cytometry. The AgarCyto cell block protocol is an excellent tool for inventory studies of diagnostic and potentially prognostic molecular markers of cervical cancer.

Detection of circulating anti-p53 antibodies in esophageal cancer patients

It has been reported that circulating anti-p53 antibodies (p53-Ab) in the serum are detected in some cancers. To investigate the usefulness of detecting p53-Ab, we measured the circulating p53-Ab in comparison with squamous cell carcinoma antigen (SCC-Ag) in patients with esophageal carcinoma. Serum specimens from 46 esophageal cancer patients (42 squamous cell carcinomas, 3 mucoepidermoid carcinomas and 1 basaloid squamous carcinoma) and 13 healthy subjects were studied. Serum p53-Ab was measured by an enzyme-linked immunosorbent assay. Surgically resected specimens from 43 patients were immunohistochemically stained for p53. Serum SCC-Ag was measured by a radioimmunoassay. The results were analyzed with the clinical data and outcome. Serum p53-Ab was detected in 13 (28%) of the 46 patients, but not in any of the healthy subjects. The positive rate was 0% (0/6) in stage I, 60% (3/5) in stage IIA, 30% (3/10) in stage IIB, 29% (7/24) in stage III and 0% (0/1) in stage IV. There was no difference in the outcome between the p53-Ab-positive and p53-Ab-negative patients. Immunohistochemically, 30 (70%) of the 43 specimens stained positively for p53. Serum p53-Ab was detected in 43% (13/30) of the patients with tumors which stained positively for p53. There was a close correlation between positivity for p53 immunostaining and positivity for p53-Ab (p<0.01). An elevated level of SCC-Ag was found in only 13%of the patients, and most patients positive for SCC-Ag already had advanced disease with lymph node metastasis and invasion to the adventitia. In conclusion, serum p53-Ab was detected in Japanese esophageal cancer patients at a frequency similar to that reported in Western countries. Serum p53-Ab may be a potentially useful molecular marker for detection and screening of esophageal cancer. Further studies of a large population may be required to elucidate the true diagnostic usefulness of measuring the serum p53-Ab.

The possible role of p53 and bcl-2 expression in cervical carcinomas and their premalignant lesions

OBJECTIVE

The purpose of this study was to assess the expression and clinical significance of bcl-2 and p53 in the progression of cervical neoplasias.

METHODS

One hundred seventy-one cervical specimens, consisting of normal cervical epithelium (n = 13), lesions with histological features of HPV infection (n = 14), CIN (cervical intraepithelial neoplasia) lesions (n = 63), and cervical carcinomas (n = 81) were examined immunohistochemically in paraffin sections.

RESULTS

Twenty-three specimens showed p53 expression [3/20 (15%) CIN III, 18/63 (29%) ISCC (invasive squamous cervical carcinoma), and 2/18 (11%) adenocarcinomas] while 63 cases expressed the bcl-2 gene [10/13 (77%) normal, 0/14(0%) condylomas, 6/23 (26%) CIN I, 9/20 (45%) CIN II, 15/20 (75%) CIN III, 18/63 (29%) ISCC, and 5/18 (28%) adenocarcinomas]. The expression of bcl-2 was found to increase in direct relation to the grade of CIN (P = 0.02) whereas such a trend was not observed for p53. p53 was not detected in normal or premalignant lesions (except 3 out of 20 cases of CIN III). There was no significant correlation between the expression of p53 and the histological type of cervical carcinoma, even though expression of p53 was higher in ISCC than in adenocarcinomas (29% vs 11%, respectively). In cervical cancer patients, expression of bcl-2 was correlated to a greater than 5-year survival (P < 0.01) while no prognostic significance of p53 expression was found.

CONCLUSION

Evaluation of bcl-2 expression may provide additional and independent prognostic information for the clinical course of the disease and therefore to be developed as a prognostic indicator for cervical cancer.

p53 immunohistochemical expression of Egyptian cervical carcinoma

Data concerning the expression of p53 in cervical carcinoma, one of the leading cause of death in developing countries, are still confusing. This study was designed to identify p53 in Egyptian cervical carcinoma in an attempt to evaluate its prognostic significance. Eleven chronic cervicitis and 38 invasive carcinoma (31 squamous cell carcinoma (sqcc) and 7 adenocarcinoma, ranging from stage IB to IVB), were stained with the monoclonal antibody anti p53, DO7, using the microwave for antigen retrieval. No immunoreactivity was detected in chronic cervicitis, while nuclear p53 reactivity was detected in all carcinoma and in squamous intra-epithelial lesions (SIL) overlying 8 sqcc. P53 immunohistochemical (IHC) expression was more pronounced in early clinical stages (p=0.007) and in adenocarcinoma compared to sqcc (p=0.015). A positive correlation was present between p53 and heat shock protein 70 (hsp70) expressions (p=0.005). No correlation could be found between p53 expression and tumor infiltrating lymphocytes, the presence or absence of either schistosomiasis or HPV infections. It can be concluded, that in the Egyptian population, p53 immunoreactivity appears to be an early event in cervical neoplasm, and seems to play an important role together with other cell regulatory proteins in the process of carcinogenesis, which could be different between sqcc and adenocarcinoma.

An immunohistochemical analysis of heat shock protein 70, p53, and estrogen receptor status in carcinoma of the uterine cervix

OBJECTIVES

It has been shown that heat shock proteins (HSPs) protect cells from death caused by various noxious stimuli. Overexpression of HSP70 seems to be related to hormonal regulation of cell proliferation and/or down-regulation of sex steroid receptors. Wild-type p53 has been reported to repress HSP70 gene expression. It has been shown that mutant p53-HSP70 complex is highly expressed in cancer. However, the relationship between HSPs and steroid receptors or tumor suppressor gene products has not been well understood in uterine cervical carcinoma. This study was undertaken to examine the expression of HSP70, estrogen receptor (ER), and p53 in carcinoma of the uterine cervix. In addition, we analyzed HPV infection status and compared it to such immunohistochemical parameters. We also analyzed the relationship between these biological products and their clinicopathologic characteristics.

METHODS

Paraffin-embedded tissue sections were obtained from 84 patients with carcinoma of the uterine cervix. Expression of HSP70, p53, and ER was evaluated by immunohistochemical staining using anti-HSP70 monoclonal antibody (SPA810), anti-p53 (BP53.12), and ER1D5 antibody, respectively. PCR HPV detection was done by dot hybridization method.

RESULTS

Positive staining of HSP70 was detected in 73% of the cases. HSP70 positivity was significantly higher in stage I cervical cancer than in stages II-IV (P = 0.02). This was associated with neither tumor size, lymph node status, parametrial involvement status, nor tumor markers (TA-4). Furthermore, there was no significant correlation between HSP70 positivity and the expression of p53 or ER or HPV infection status.

CONCLUSION

These data suggested that HSP70 positivity was frequent in uterine cervical cancer, especially in the early stages. However, this was not significantly correlated with clinicopathologic characteristics nor with the expression of p53 or ER nor with HPV infection in carcinoma of the uterine cervix.

Comparison of different scoring systems for immunohistochemical staining

AIM

To carry out an objective assessment of two systems of scoring immunohistochemical staining, evaluating interobserver and intraobserver error.

METHODS

92 cervical tumours underwent immunohistochemical staining for p53 and epidermal growth factor receptor. Staining was assessed using two methods: a standard 4 point scale and a descriptive method, performed by three observers. Interobserver and intraobserver error were assessed for both scoring methods.

RESULTS

In terms of interobserver error between three observers, no difference was found between a simple 4 point scale method of evaluation and the use of a highly circumscribed method. In all evaluations, interobserver error was scored as moderate (kappa w 0.48-0.49). However, evaluation of immunohistochemical staining by a panel of observers led to a marked improvement in the interobserver error scores (kappa w 0.63).

CONCLUSIONS

There should be standardisation of immunohistochemical staining and scoring methods. More attention should be paid to measurement of interobserver and intraobserver error in studies. Use of a panel of tissue control slides and consensus scoring by several observers can lead to improvement in reproducibility.

Human cervical cancer-associated nuclear matrix proteins

The nuclear matrix is the nonchromatin protein structural component of the nucleus that governs nuclear shape and also exerts regulatory control over higher order gene organization. Recent studies have documented the presence of tumor-associated nuclear matrix proteins in several human cancers. We used high-resolution two-dimensional gel electrophoresis to compare nuclear matrix protein patterns in cervical carcinomas with those from normal cervical tissue. Tumors obtained from 20 patients undergoing hysterectomy for clinically localized cervical cancer were compared with normal cervical tissue. We have identified five polypeptides (CvC-1: Mr = 69,408 Da, pI = 5. 78; CvC-2: Mr = 53,752 Da, pI = 5.54; CvC-3: Mr = 47,887 Da, pI = 5. 60; CvC-4: Mr = 46,006 Da, pI = 5.07; and CvC-5: Mr = 44,864 Da, pI = 6.61) in the nuclear matrix from cervical carcinomas that were present in 20 of 20 cervical tumors but 0 of 10 normal tissues. These data extend similar findings of cancer-associated nuclear matrix proteins in other human cancers and suggest that nuclear matrix proteins may represent a new class of cancer markers that could aid the diagnosis or management of some types of cancer.

p53 protein immunoreactivity in fibrohistiocytic tumors of the skin

Abnormal expression of the 53 kDa nuclear phosphoprotein produced by the p53 gene is observed in many human cancers. p53 nuclear immunoreactivity is found commonly in tumor cells. Immunohistochemistry was performed using a monoclonal antibody, DO-7 (DAKO, Denmark; cat. no. M7001; 1:100 dilution), to investigate p53 protein immunoreactivity in a group of cutaneous fibrohistiocytic tumors that are known to be locally aggressive. The study group consisted of dermatofibrosarcoma protuberans (DFSP) (n = 14) and atypical fibroxanthoma (AFX) (n = 7). Cases of dermatofibroma (DF) (n = 16) formed the benign control group. Intense nuclear immunostaining for p53 protein was observed in 71% of DFSP and 86% of AFX. None of the dermatofibromas showed strong p53 nuclear immunostaining. Statistical analyses revealed significant differences in p53 immunoreactivity between DFSP and DF (P = 0.0001, chi 2 test) and between AFX and DF (P = 0.0001, chi 2 test). In conclusion, increased p53 protein immunoreactivity is found in DFSP and AFX but not in DF. These differences in p53 immunoreactivity suggest that increased expression of the protein may be important in the pathogenesis of the more aggressive group of fibrohistiocytic tumors.

Immunohistochemical detection of sex steroid receptors, cyclins, and cyclin-dependent kinases in the normal and neoplastic squamous epithelia of the uterine cervix

BACKGROUND

Malignant transformation of sex steroid-dependent tissues has been reported to be associated with abnormal expression of sex steroid receptors. In addition, abnormalities of cell cycle-related molecules have been demonstrated in various malignancies. However, expression of steroid receptors and cell cycle-related molecules in the process of malignant transformation of the ectocervical squamous epithelium, which also is a sex steroid-dependent tissue, has not been elucidated fully.

METHODS

Immunohistochemical staining was performed on formalin fixed, paraffin embedded tissue sections of normal squamous epithelia (30 cases), cervical intraepithelial neoplasia (CIN) (21 cases), and invasive squamous carcinoma (SCC) (33 cases), using antibodies against estrogen receptors (ER), progesterone receptors (PR), cyclins (E, A, and B1), cyclin-dependent kinases (cdk2 and cdc2), and p53 protein. In addition, growth activity of SCC was evaluated by Ki-67 labeling.

RESULTS

In the normal epithelia, diffuse proportionate to regional expression of ER/PR and sporadic expression of cyclins/cdks were observed mainly in the parabasal cells irrespective of the menstrual cycle. In the neoplastic lesions, the expression of ER markedly decreased; however, the expression of PR increased. The expression of cyclins, cdks, and p53 was increased in a considerable number of these neoplastic cases. In addition, cyclin A positive SCC had elevated Ki-67 labeling, whereas cyclin E positive SCC cases had lower Ki-67 labeling.

CONCLUSIONS

These findings suggest that malignant transformation of ectocervical epithelia is associated with loss of normal growth control by steroid hormones as well as with the acquisition of abnormal cell cycle regulatory mechanisms.

Papillary serous carcinoma of the uterine cervix: a clinicopathologic study of 17 cases

The clinical and pathologic features of 17 cases of papillary serous adenocarcinoma of the cervix (PSCC) were studied in women who ranged in age from 26 to 70 years. There was a bimodal age distribution, with one peak occurring before the age of 40 years and the second peak after the age of 65. The presenting symptoms were abnormal vaginal bleeding (11 patients), abnormal exfoliative cervical cytology (four patients), or watery vaginal discharge (two patients). On pelvic examination, eight patients had a polypoid or exophytic cervical mass and two patients had an ulcerated or indurated cervix; no abnormality was detected in seven patients. Two tumors were stage Ia, 12 were stage Ib, two were stage II, and one was stage III. Nine patients were treated by radical hysterectomy and one by simple hysterectomy; six of these patients received postoperative radiotherapy. The other patients received primary radiotherapy. On microscopic examination, all of the tumors had a complex papillary architecture with epithelial stratification and tufting. Six tumors were grade 2/3 and 11 were grade 3/3. All of the tumors had >10 mitotic figures per 10 high-power fields. An intense acute and chronic inflammatory infiltrate was typically present within the cores of the papillae and in areas of stromal invasion. Occasional psammoma bodies were present in three cases. Five of 12 tumors stained positively for p53, with six and nine of 12 tumors, respectively, immunoreactive for carcinoembryonic antigen and CA-125. Seven tumors were mixed with another histologic subtype of cervical adenocarcinoma, most commonly low-grade villoglandular adenocarcinoma. Fifteen patients were followed from 6 months to 11 years (mean 56 months). Six patients died of extensive metastases within 5 years of diagnosis; an additional patient experienced tumor recurrence with malignant ascites 2 years after diagnosis. The most common metastatic sites were pelvic and periaortic lymph nodes; other sites included cervical lymph nodes, lung, peritoneum, liver, and skin. Eight patients were alive without evidence of tumor at last follow-up. Age <65 years, stage >I, tumor size >2 cm, tumor invasion >10 mm, the presence of lymph node metastases, and elevation of serum CA-125 were associated with a poor prognosis. Tumor grade or composition (pure or mixed) did not correlate with patient outcome. Papillary serous adenocarcinoma of the cervix resembles microscopically its counterparts elsewhere in the female genital tract and peritoneum. The tumors can behave aggressively with supradiaphragmatic metastases and a rapidly fatal course when diagnosed at an advanced stage, but the outcome for patients with stage I tumors is similar to that of patients with cervical adenocarcinomas of the usual type.

A comparison of different modes for the detection of p53 protein accumulation. A study of bladder cancer

The aim of the present study was to evaluate different techniques for the analysis of p53 protein accumulation in human bladder cancer. The accumulation was evaluated in 23 carcinomas by immunoblotting (IB), immunohistochemistry (IHC) and flow cytometry (FCM). The results revealed that six (26%), eight (35%) and ten (43%) of the tumours were p53 protein positive by IB, IHC and FCM, respectively. Mutation analysis of the TP53 gene confirmed mutations in 8 of 9 tumours which showed increased levels of p53 protein by FCM. Our results indicate that IHC could be applied for studies of p53 protein accumulation in archival formalin fixed, paraffin-embedded bladder tumours. However, FCM is a more sensitive and objective method for the detection of p53 protein than IHC and this should be taken into account when routinely evaluating the p53 protein accumulation by IHC.

p53 and proliferating cell nuclear antigen in endocrine tumors of pancreas and intestinal carcinoids

Twenty six endocrine tumors of the pancreas and 19 carcinoids of the intestinal tract were studied with immunocytochemical staining for p53 and proliferating cell nuclear antigen (PCNA) to detect any correlation between PCNA and p53 immunostaining. PCNA immunostaining is somewhat variable in endocrine tumors of the pancreas whereas p53 overexpression was detected in one out of eight insulinomas (12.5%), four out of eight gastrinomas (50%) and none of two glucagonomas, six PPomas and two non-functioning tumors. In 19 intestinal carcinoids, two of eight small-intestinal carcinoids (25%) were positive for p53 whereas five appendiceal and two colonic carcinoids were negative for p53. It was concluded that: 1. PCNA staining is variable with no clear distinction between benign and malignant endocrine tumors of the pancreas and intestinal carcinoids, although positive PCNA staining may assess growth fraction of tumors; 2. p53 overexpression is relatively rare both in endocrine tumors of the pancreas (one out of 18 non-gastrinomas) and intestinal carcinoids, except for gastrinomas, in which 50% were positive for p53; and 3. non-neoplastic islet cells are positive for p53.

Molecular characterization of adenocarcinoma of the cervix

In an attempt to characterize the molecular alterations of cervical adenocarcinoma, we analyzed 32 paraffin-embedded specimens for the presence of K-ras mutations, p53 overexpression, p16 and Rb protein expression, and the presence of HPV 16 and 18 DNA. Overall 25/32 (78%) of the tumors displayed an abnormality in at least one of these analyses. K-ras mutations were detected by PCR amplification and RFLP analysis in 3 tumors, including 2 at codon 12 and 1 at codon 61. p53 overexpression determined by immunohistochemistry was demonstrated with > 80% of tumor nuclei staining in 4 cases, 10-15% of nuclei staining in 3 cases, and < 1% of nuclei staining in 5 cases. The pattern of staining was diffuse in 6 cases, focal in 1 case, and scattered in 5 cases. Analysis of p16 protein expression in 23 specimens revealed 1 tumor with abnormal staining, while Rb protein expression was determined to be normal in all 25 tumors tested. HPV DNA, detected by PCR with type-specific primers, was found in 16 tumors (50%), including 7 (22%) with HPV 16 and 9 (28%) with HPV 18. There was no correlation among these abnormalities except that the presence of HPV and strong p53 overexpression (> 80% tumor nuclei staining) were mutually exclusive events. Clinical correlation demonstrated that p53 overexpression involving the majority of tumor cell nuclei is characteristic of advanced stage disease, while HPV positivity and activated ras genes are associated with early stage disease.

p53 expression in carcinoma of the cervix

AIM

To assess overexpression of the proposed tumour suppressor gene product p53 using the mouse monoclonal antibody DO-7 in the three main subtypes of carcinoma of the uterine cervix and to evaluate its value as a prognostic indicator.

METHODS

Eighty two cases of FIGO Stage IB/IIA uterine cervical carcinoma were studied retrospectively. The tumours had been previously typed into adenocarcinomas, squamous carcinomas and adenosquamous carcinomas after the tissue had been fixed in formalin and embedded in paraffin wax. p53 protein expression was assessed using a standard immunohistochemical technique and the findings were correlated with tumour type, lymph node status and clinical outcome.

RESULTS

In total, the p53 gene product was overexpressed in 17.1% (14/82) of all carcinomas and also in areas of cervical intraepithelial neoplasia grade III adjacent to invasive squamous carcinoma. Where present, the normal epithelium was uniformly negative. No association was found between p53 overexpression and tumour subtype, lymph node status or clinical outcome.

CONCLUSIONS

It seems unlikely that p53 analysis will be of value in determining prognosis in carcinoma of the uterine cervix.

Immunohistochemistry (Ki-67 and p53) as a tool in determining malignancy in smooth muscle neoplasms (exemplified by a myxoid leiomyosarcoma of the uterus)

Smooth muscle tumours of the uterus at times represent a problem as it may be difficult to distinguish between benign and malignant tumours. The myxoid leiomyosarcoma (a rare type of neoplasm) reported here is an example of this. We present a case history and examine the suitability of Ki-67 and p53 as indicators of malignancy. The two antibodies were tested on seven leiomyomas, three atypical (borderline) leiomyomas, seven leiomyosarcomas and the myxoid leiomyosarcoma using microwave oven antigen retrieval. The leiomyomas had the lowest and the leiomyosarcomas the highest proliferation rate. The leiomyomas had no expression of p53, the atypical leiomyomas had a few scattered positive nuclei, and 5/7 of the leiomyosarcomas had overexpression of p53. The myxoid leiomyosarcoma had a positive reaction for p53 in clusters. The results suggest that Ki-67 and p53 might be useful as indicators of malignancy.

TP53 alterations in atypical ductal hyperplasia and ductal carcinoma in situ of the breast

Abnormalities in the TP53 tumour suppressor gene in 75 atypical ductal hyperplasias and 62 ductalcarcinomas in situ (DCIS) of the breast were studied using immunohistochemistry and mutation analysis. Accumulation of p53 protein was detected in 10 out of 62 (16%) DCIS, whereas no cases of positive staining was observed in the atypical lesions. TP53 mutations were identified in four out of 30 (13%) DCIS by constant denaturant gel electrophoresis (CDGE). Two of these cases were positive and two negative for p53 protein. A total of 12 out of 62 DCIS (19%) carried TP53 mutation and/or p53 protein over-expression. The present results suggest that TP53 alterations may be important in the development of a subset of DCIS.

An immunohistochemical study of p53 protein in cervical intraepithelial neoplasia and squamous cell carcinoma

p53 mutations are known to occur frequently in human cancers where they are considered to be an important event in the stepwise progression towards malignant transformation. It is therefore interesting to compare p53 expression in the uterine cervix for non-neoplastic/metaplastic squamous epithelium, cervical intraepithelial neoplasia (CIN) and invasive squamous cell carcinoma. One hundred and nineteen biopsied and resected specimens of the uterine cervix were stained with an anti-human p53 protein monoclonal antibody by the streptavidin-biotin immunoperoxidase method. Histologically these could be categorized into non-neoplastic/dysplastic conditions, including condyloma (34 cases), CIN 1-3 (66 cases) and invasive squamous cell carcinoma (19 cases). Fifty eight per cent (11/19) of the invasive squamous cell carcinomas and 11% (7/66) of the CIN stained positively for p53. Except for 3 cases of invasive squamous cell carcinoma, there was only sporadic intranuclear staining of less than 5% of the cells. No staining was observed in all non-neoplastic/metaplastic squamous epithelial cells. The pattern of p53 staining is significantly different for all 3 categories. However it is undetermined as to whether the positive immunoperoxidase staining is a direct consequence of p53 gene mutation or otherwise.

Chemoprevention trials and surrogate end point biomarkers in the cervix

Cervical cancer is the second most common malignancy in women worldwide and remains a significant health problem for women, especially minority and underserved women. Despite an understanding of the epidemiologic risks, the screening Papanicolaou smear, and morbid and costly treatment, overall survival remains 40%. New strategies, based on the clinical and molecular aspects of cervical carcinogenesis, are desperately needed. Chemoprevention refers to the use of chemical agents to prevent or delay the development of cancer in healthy populations. Chemoprevention studies have several unique features that distinguish them from classic chemotherapeutic trials; these features touch on several disciplines and weave knowledge of the biology of carcinogenesis into the trial design. In the design of chemoprevention trials, four factors are important: high risk cohorts must be identified; suitable medications must be selected; study designs should include Phases I, II, and III; and studies should include the use of surrogate end point biomarkers. Surrogate end point biomarkers are sought because the cancer develops over a long period of time, and studies of chemopreventives would require a huge number of subjects followed for many years. Surrogate end point biomarkers serve as alternative end points for examination of the efficacy of chemopreventives in tissue. High risk cohorts include women with cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesions (SIL). Nutritional studies have helped define micronutrients of interest (folate, carotenoids, vitamin C, vitamin E). Other medications of interest include retinoids (4-hydroxyphenylretinamide [4-HPR], retinyl acetate gel, topical all-trans-retinoic acid), polyamine synthesis inhibitors (alpha-difluoromethylornithine [DFMO]), and nonsteroidal anti-inflammatory drugs (ibuprofen). Phase I chemoprevention studies of the cervix have tested retinyl acetate gel and all-trans-retinoic acid. Phase II trials of all-trans-retinoic acid, beta-carotene, and folic acid have been and are being carried out, whereas Phase III trials of all-trans-retinoic acid have been completed and have shown significant regression of CIN 2 but not CIN 3. Phase I studies of DFMO and Phase II studies of DFMO and 4-HPR are underway. Surrogate end point biomarkers under study include (1) quantitative cytology and histopathology; (2) human papillomavirus type testing; (3) biologic measures of proliferation, regulation, differentiation, and genomic instability; and 4) fluorescence spectroscopic emission. Clinical trials with biologic end points will contribute to our understanding of the neoplastic process and hence aid us in developing new preventive and therapeutic strategies.

Modulation of expression of p53 and cell proliferation in locally advanced cervical carcinoma after neoadjuvant combination chemotherapy

OBJECTIVE

In the present study, we investigated changes of p53 expression and the cell proliferation index detected with MIB 1 in tumors before and after neoadjuvant combination chemotherapy with respect to the outcome of the disease. Our aim was to define more appropriately the significance of chemotherapy in locally advanced cervical carcinoma.

MATERIALS AND METHODS

Our study included 17 women with locally advanced squamous cervical carcinoma who had been admitted to the Institute of Gynecology and Obstetrics Ancona University, between January 1990 and December 1994. The patients received neoadjuvant combination chemotherapy consisting of three cycles of cisplatin (80 mg/m2) and bleomycin (30 mg/m2). After chemotherapy, radical surgery was performed. Bioptic specimens were obtained from cervical tumors before and after chemotherapy and processed for immunohistochemical staining with a monoclonal antibody against p53 and with the monoclonal antibody MIB 1.

RESULTS

Thirteen patients (76.5%) showed a clinical response (4 complete and 9 partial), while of the remaining 4 cases (23.5%) 3 had no change and 1 showed progression after neoadjuvant combination chemotherapy. A significant relationship was observed between the overexpression of p53 and the sensitivity to chemotherapy; responder patients showed a higher frequency of p53 positive cells than non-responders (P = 0.03). No significant relationship with MIB 1 index was observed. Both expression of p53 protein (P < 0.001) and reaction with MIB 1 (P = 0.003) significantly decreased after chemotherapy. The decrease in expression of p53 protein and staining with antibody MIB 1 was particularly evident in patients who responded to chemotherapy.

DISCUSSION

In tumors, p53 protein and index of proliferating cells as determined with MIB 1 showed a significant modulation after treatment, suggesting an association with sensitivity to chemotherapy. However, the limited number of our series of patients does not permit a statement on the clinical implication of expression of p53 and cell proliferation in patients undergoing neoadjuvant combination chemotherapy for locally advanced cervical carcinoma.

p53 in cutaneous melanoma: immunoreactivity and correlation with prognosis

p53 protein immunoreactivity was investigated in cutaneous Spitz naevi (n = 7), superficial spreading (n = 21) and nodular (n = 6) melanomas using the monoclonal antibody DO-7. Nuclear immunostaining for p53 protein was observed in 41% of all the melanomas but not in any of the Spitz naevi studied. This difference in p53 immunoreactivity appeared statistically significant (P = 0.0001; chi 2 test). There were also differences in p53 immunoreactivity between superficial spreading and nodular melanomas (P = 0.001, chi 2 test), where up to 38% of superficial spreading melanomas and 50% of nodular melanomas had demonstrated p53 nuclear immunostaining. An apparently significant correlation was observed between melanomas with poor prognostic histological indices and p53 immunoreactivity (P = 0.0016; chi 2 test). In conclusion, increased p53 protein immunoreactivity is found in melanomas and is associated with poorer prognosis. The differences in p53 immunohistological expression between cutaneous melanomas and Spitz naevi suggest that alterations of the protein may be important in the pathogenesis of the tumour.

TP53 gene mutations and protein accumulation in primary vaginal carcinomas

Primary carcinomas from 46 patients were screened for TP53 alterations. Immunohistochemistry demonstrated nuclear TP53 protein accumulation in 22 (48%) cases using the polyclonal CM1 antiserum, whereas 15 (33%) cases showed positive nuclear staining with the mononuclear antibody PAb 1801. Constant denaturant gel electrophoresis (CDGE) was used to screen 27 of the vaginal carcinomas for mutations in the conserved regions of the TP53 gene (exons 5-8). Six of these tumours (22%) contained mutations: four were found in exon 5 and two in exon 8. A total of 50% of the primary vaginal carcinomas carried a TP53 alteration. These results indicate that TP53 abnormalities may be involved in the development of these tumours. However, there was no significant association between TP53 abnormalities and survival.

p53 protein expression in sequential biopsies of oral dysplasias and in situ carcinomas

Immunohistochemically detectable levels of p53 may be seen early in the malignant transformation of some neoplasms. To determine if p53 is immunocytochemically detectable, and therefore presumptively abnormal, in oral dysplasias and in situ carcinomas, and to explore the natural history of p53 protein expression in these lesions, sequential biopsies from patients with lesions occurring in the same anatomic site were examined. Formalin-fixed, paraffin-embedded sections from 19 patients were evaluated immunohistochemically for p53 protein using antibody clones Pab1801 and BP53-12. With two exceptions, comparable results were observed with these antibodies. p53 protein was detected immunocytochemically in 6 of 13 patients with dysplasias; 3 of these progressed to p53-positive invasive carcinoma, one advanced to a more severe grade of p53-positive dysplasia, one developed into a p53-negative verrucous carcinoma, and one represented a p53-positive dysplasia developing five years after treatment of a p53-positive carcinoma. The p53-positive dysplasias, which were found in all subtypes (mild, moderate, severe), preceded histologic malignant change by months to years. p53 detection was evident in 4 of 6 patients with in situ lesions. Sequential biopsies of three of these lesions showed no change in lesion histology or p53 staining, and one lesion advanced to a p53-positive carcinoma. It is concluded that p53 protein may be detected early in the development of a subset of p53-positive oral squamous cell carcinomas. This phenomenon may be seen in dysplasias and in situ lesions, and it may have prognostic implications.

Immunohistochemical detection of p53 in cervical epithelial lesions with or without infection of human papillomavirus types 16 and 18

Using formalin-fixed and paraffin-embedded cervical tissues, we examined infection with human papillomavirus (HPV) types 16 and 18 by Southern blot analysis following polymerase chain reaction (PCR), and the accumulation of p53 protein by immunohistochemistry in 30 cases of normal or metaplastic cervix, 17 cases of cervical intraepithelial neoplasia grade I (CIN I), 20 cases of CIN II, 37 cases of CIN III and 23 cases of invasive squamous cell carcinoma (ISCC). In addition, we examined the ratio of HPV-infected cells by in situ hybridization (ISH) and the alteration of p53 gene using PCR followed by single-strand conformation polymorphism (PCR-SSCP) in 2 cases of CIN III and 12 cases of ISCC, in which overexpression of p53 was immunohistochemically detected. HPV DNA was detected in 5 cases (16.7%) of normal or metaplastic cervix, 5 cases (29.4%) of CIN I, 9 cases (45.0%) of CIN II, 26 cases (70.3%) of CIN III and 15 cases (65.2%) of ISCC. Positivity for HPV in the groups of CIN III and ISCC was significantly higher than in the normal or metaplastic cervix (P < 0.05). The accumulation of p53 was not detected in the normal or metaplastic cervix, CIN I and CIN II. High-level p53 accumulation was identified in basal and suprabasal atypical cells in 27.0% (10/37) of CIN III and in carcinoma cells in 43.5% (10/23) of ISCC cases, and low-level accumulation was identified in atypical cells of 35.1% (13/37) of CIN III and in carcinoma cells in 30.4% (7/23) of ISCC cases. The accumulation of p53 was found to coexist with infection by HPV in 17 (46.0%) of 37 CIN III cases and 12 (52.2%) of 23 ISCC cases, and high-level p53 accumulation was more frequently detected in HPV-positive ISCC cases. Either HPV infection or accumulation of p53 was found in 16.7% (5/30) of the cases of normal or metaplastic cervix, 29.4% (5/17) of CIN I, 45.0% (9/20) of CIN II, 86.5% (32/37) of CIN III and 87.0% (20/23) of ISCC cases. These results suggest that the inactivation of p53 function by HPV infection or alteration of p53 protein itself precedes the development of tumours with a fully malignant and invasive phenotype and plays an important role in tumorigenesis in the uterine cervix. ISH study provided no correlation between the degree of immunohistochemical positivity for p53 and the ratio of HPV-positive cells in the same lesions.(ABSTRACT TRUNCATED AT 400 WORDS)

The relationship between proliferating cell nuclear antigen (PCNA), nuclear DNA content and mutant p53 during genesis of cervical carcinoma

Proliferating cell nuclear antigen (PCNA), nuclear DNA content and mutant p53 overexpression were studied by means of image cytometry and immunohistochemistry respectively in normal mucosa (n = 10), in mild (n = 16), moderate (n = 9) and severe (n = 17) atypical lesions, as well as in squamous cell carcinomas (n = 36) of the cervix uteri. The results show that increasing histopathological atypia in the cervical mucosa was correlated to an initial increase of PCNA followed by distinct aneuploidy and p53 overexpression. The data are suggested to contribute to a better understanding of the genesis of cervical carcinoma, and to indicate that the coexistence of both distinct aneuploidy and p53 immunoreactivity can be used to decide if a cell population is neoplastic, whereas the absence of p53 overexpression does not necessarily exclude neoplasia. This diagnostic procedure can be suggested to improve early detection of intraepithelial squamous neoplasia.

p53 immunoreactivity in cervical intraepithelial neoplasia and non-neoplastic cervical squamous epithelium

AIMS

To determine the pattern of p53 immunoreactivity in cervical squamous epithelium and to investigate the relation between p53 immunostaining and human papillomavirus (HPV) infection.

METHODS

Immunocytochemistry for p53 was performed in 65 specimens of formalin fixed, paraffin wax embedded cervical tissue using a polyclonal antibody against recombinant p53. Microwave oven heating was used for antigen retrieval. Eight normal biopsy specimens, eight cases with histological features of HPV infection, and 49 cases of cervical intraepithelial neoplasia (CIN) were examined. Thirty one cases of CIN were examined. Thirty one cases of CIN were examined for evidence of HPV infection using in situ hybridisation with probes directed against wide spectrum HPV, HPV 16 and HPV 18.

RESULTS

p53 immunoreactivity was seen in seven of eight (87%) of specimens with histological features of HPV infection, five of eight (62%) normal specimens, 13 of 22 (59%) CIN III, three of 14 (21%) CIN II and five of 13 (38%) CIN I specimens. The numbers of positive nuclei were small in cases of CIN and the location of positive nuclei within the epithelium paralleled the degree of dysplasia. Eleven of 15 (73%) CIN specimens which were immunoreactive for p53 yielded a positive signal for HPV by in situ hybridisation. A positive signal for HPV was also seen in 10 of 16 (63%) of CIN specimens in which p53 staining was absent.

CONCLUSIONS

p53 immunoreactivity can be demonstrated in a small proportion of cells in the cervical squamous epithelium in a significant proportion of cases of CIN. This immunoreactivity seems to be independent of the presence of HPV, as assessed by in situ hybridisation. p53 immunoreactivity also occurs in non-neoplastic cervical squamous epithelium with a pattern of distribution within the epithelium which differs from that seen in CIN. Antigen retrieval by microwave oven heating enhances p53 immunostaining and may result in visualisation of cellular p53 in the absence of mutation.

p53 gene mutation is rare in human cervical carcinomas with positive HPV sequences

Chromosome 17p allelic losses and concurrent p53 mutations have been demonstrated in various human cancers. We therefore investigated the presence of chromosome 17p allelic loss and possible concurrent p53 mutation in 29 Korean cases of cervical carcinoma by restriction fragment length polymorphism (RFLP) analysis and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) over the region from exon 4 to exon 9 of the p53 gene. We also examined the expression of p53 in paraffin tissues by immunohistochemical staining and determined the incidence of human papillomavirus (HPV) sequences in the same tissues by multitype PCR analysis to correlate them to the allelic loss on chromosome 17p13 and p53 mutation. In the analysis of 29 cases, loss of heterozygosity (LOH) was observed in eight (40%) cases out of 20 informative cases and p53 mutation was observed in only one case (3.4%) at exon 5. So in the majority of cases with LOH on 17p in this series, mutation of p53 gene appeared to be rare. But we obtained three cases (10.3%) of positive immunoreactivity from 29 cases. Those cases may carry mutations outside of the regions examined by PCR-SSCP. HPV DNA was detected in 27 of 29 cases (93.1%). HPV types 8, 11, 16, and 18 were detected in the samples we tested, while only two (7.4%) out of 27 HPV positive cases exhibited overexpression for p53 without any demonstrable p53 mutation upon PCR-SSCP. These results suggest that HPV infection may play a role in inactivating wild-type p53 protein in cervical carcinomas. In conclusion, mutation and overexpression of p53 gene appear to be rare, particularly in cases of cervical carcinoma associated with positive HPV sequence.

HPV-associated epithelial atypia in oral warts in HIV+ patients

Reported are oral mucosal warts (HPV common antigen-positive) from 7 adult HIV+ patients in which there was cytologic atypia and disordered growth. Lesions were papillary, white to red in color, and were located on the lip, gingiva, palate, tongue, and buccal mucosa. Histologically, the keratinocytes in the lesions exhibited atypical features in the form of hyperchromatism and karyomegaly. Koilocytes were frequently seen in the upper level keratinocytes where HPV common antigen was identified. The dysplastic areas, which ranged from mild to severe, typically showed abrupt limiting margins. All lesions exhibited intense PCNA reactivity from basement membrane to surface. Nuclei of mid-level and basal keratinocytes of 3 specimens stained positively for p53 protein. We believe that the atypia found in these lesions represents cytologic change that has malignant potential. The subtype of the HPV in these lesions has not yet been determined.

TP53 allele loss, mutations and expression in malignant melanoma

p53 alterations at the DNA, mRNA and protein levels were studied in tumour metastases sampled from 30 patients with malignant melanoma. Paraffin-embedded sections from these and an additional 12 patients were examined for the presence of p53 protein. TP53 gene aberrations were found in 7 of 30 (23%) of the patients, six of which showed loss of heterozygosity (LOH). Point mutations were detected in only two cases, one of which had LOH whereas the other was non-informative. Increased levels of p53 mRNA were present in only one tumour with, but in six cases without, detectable DNA abnormalities. Four of the latter and six tumours with normal transcript levels had immunohistochemically detectable levels of p53 protein. In 25 cases in which corresponding primary and metastatic lesions could be compared, closely similar immunoreactivity patterns were observed. Increased expression of the MDM2 gene was found in only one tumour in parallel with overexpression of p53. Altogether, the data indicate that inactivation of the p53 regulatory pathway is not of major significance in the tumorigenesis of malignant melanoma. However, a significant association was found between p53 immunoreactivity and the relapse-free period in patients with superficial spreading melanoma. That increased protein expression was predominantly found in tumours without DNA alterations might suggest a role for the wild-type p53 protein in restricting malignant cell proliferation in these cases.

Variations in immunohistochemical detection of p53 protein overexpression in cervical carcinomas with different antibodies and methods of detection

Immunocytochemical detection of p53 protein products in paraffin sections is possible with a number of antisera, monoclonal and polyclonal. Few corroborative results amongst different laboratories have been published due to variations in the antibodies, the fixation protocols, and the immunocytochemical methods applied. Antigen unmasking methods employing microwaves or proteolytic enzymes add to the disparity in the percentage of positive cases reported. In this study, paraffin sections of 55 cases of cervical carcinoma were immunostained with monoclonal antibodies p53-DO7 and p53-1801 (a) without section pretreatment, (b) with pronase digestion, and (c) with microwave antigen retrieval in citric acid buffer. Specimens fixed in buffered formalin required antigen unmasking to show positive staining. Pronase digestion caused false-negative immunostaining. Microwave pretreatment with p53-DO7 yielded 100 per cent positivity for p53 proteins but only 7/55 cases with more than 50 per cent positive cells. Monoclonal antibody p53-DO7 detected more positive cases than p53-1801. Immunostaining with antibodies to p53 proteins must be interpreted cautiously as variations in fixation, antibodies, and section pretreatment will significantly affect results.

Genetic alterations of the TP53 gene, p53 protein expression and HPV infection in primary cervical carcinomas

Primary cervical carcinomas from 92 patients were investigated for genetic alterations in the tumour suppressor gene TP53. Studies of allelic imbalance (AI) were performed by Southern blot analysis and by using two PCR (polymerase chain reaction) polymorphisms within the TP53 gene. AI in the tumour was observed in 22 per cent (11 of 52 informative patients) and was significantly associated with recurrence both in a univariate (P = 0.013) and in a multivariate (P = 0.045) analysis. The DNA samples were subjected to mutation analysis of four of the conserved domains in the TP53 gene, using PCR followed by constant denaturant gel electrophoresis (CDGE). Mutations were observed in 2 of 92 tumours (2 per cent), of which one was a silent mutation and the other a frameshift. Overexpression of the p53 protein was found by immunostaining of sections from formalin-fixed, paraffin-embedded material in 55 per cent (51/92) of the tumours. In 88 per cent (45/51) of these, overexpression was present in less than 5 per cent of the tumour cells. Overexpression was significantly associated with relapse-free survival only in a univariate analysis (P = 0.045). AI of the TP53 locus did not correlate with p53 expression or mutation. The important gene on 17p, responsible for the shorter disease-free survival for patients with AI of TP53, may therefore be another gene closely linked to TP53. In addition, the 92 tumour samples were tested for the presence of human papillomavirus (HPV) types 16 and 18. Fifty-four per cent (50/92) of the samples were positive for HPV 16 using in situ hybridization, and 93 per cent (86/92) using the PCR technique. The numbers for HPV 18 were 15 per cent (14/92) and 23 per cent (21/92), respectively. Twenty-one per cent (19/92) were positive for both HPV 16 and HPV 18, while 4 per cent (4/92) were negative for both HPV 16 and 18. The tumour with the frameshift TP53 mutation was HPV 16-positive, and the four samples negative for HPV 16 and 18 did not contain TP53 mutations within the conserved domains but had elevated p53 protein expression.