Polymerase chain reaction-single strand conformation polymorphism analysis of the p53 gene in paraffin-embedded surgical material from human renal cell carcinomas

Cell-cycle arrest and senescence in TP53-wild type renal carcinoma by enhancer RNA-P53-bound enhancer regions 2 (p53BER2) in a p53-dependent pathway

TP53 is a classic tumor suppressor, but its role in kidney cancer remains unclear. In our study, we tried to explain the role of p53 in kidney cancer through the p53-related enhancer RNA pathway. Functional experiments were used to explore whether P53-bound enhancer regions 2 (p53BER2) has a role in the cell cycle and senescence response of TP53-wild type (WT) renal cancer cells in vitro or vivo. RNA-sequencing was used to identify the potential target of p53BER2. The results showed that the expression level of P53BER2 was downregulated in renal cancer tissues and cell lines, further dual-luciferase experiments and APR-256-reactivated experiments showed p53BER2 expresses in a p53-dependent way. Moreover, knockdown p53BER2 could reverse nutlin-3-induced cytotoxic effect in TP53-WT cell lines. Further exploration showed the downregulation of p53BER2 could reverse nutlin-3-induced G1-arrest and senescence in TP53-WT cell lines. What is more, the knockdown of p53BER2 showed resistance to nutlin-3 treatment in vivo. Additionally, we found BRCA2 could be regulated by p53BER2 in vitro and vivo; further experiment showed p53BER2 could induce cell-cycle arrest and DNA repair by mediating BRCA2. In summary, the p53-associated enhancer RNA-p53BER2 mediates the cell cycle and senescence of p53 in TP53-WT renal cancer cells.

Immunohistochemistry of Complement Response on Human Renal Cell Carcinoma Biopsies

The goal of the study was to characterize the complement humoral and cellular antitumor responses on primary renal cell carcinoma biopsies. As an original observation, complement activation was found on 11/22 cases. Classical complement pathway activation was characterized by tumor C1q complement protein and IgG deposition (5/22 cases). Alternative or nonimmune complement pathway activation was seen as tissue deposition of C3 (6/22 cases). The membrane attack complex was present in cases with alternative complement pathway activation at the sites of tumor necrosis. Renal cell carcinomas with complement activation overexpressed at least one of the complement regulatory factors (membrane cofactor protein, decay accelerating factor, membrane attack complex inhibitor) and major histocompatibility complex class II molecules. Tumor infiltrating lymphocytes were present in most of the renal cell carcinomas with complement activation (8/11). However, the number of tumor-infiltrating lymphocytes was correlated with the intensity of major histocompatibility complex-ll expression in 18/22 cases. Detection of complement activation and immune cell infiltrates on renal cell carcinoma primary biopsies may serve as a new predictive factor for immunotherapy.

Dysregulation of the cell cycle and chromosomal imbalances in juxtaglomerular cell tumors - a comparative study with endocrine tumors of the pancreas

Two juxtaglomerular cell tumors (JGCTs) were investigated in comparison with 14 endocrine tumors of the pancreas (ETPs), focusing on the cell cycle, apoptosis, and cytogenetic changes. JGCTs revealed nuclear accumulation of Cyclin D(1), together with the cyclin-dependent kinase inhibitors p21(Cip1/Waf1) and p27(Kip1). In contrast, no accumulation of Cyclin D(3), p53, p16(INK4a), or Mdm-2 was seen. Bcl-2 protein was intensively, but Rb only moderately, expressed. This immunoreactive profile was not found in the ETPs, which were negative for Bcl-2, p27(Kip1), p21(Cip1/Waf1), and - with one exception - for Cyclin D(1) (1/14) but expressed Cyclin D(3) in 7/14 cases. JGCTs displayed characteristic genetic alterations with combined losses of chromosomes 9, 11, 15, and 21 and gains of chromosome 18. In contrast, no characteristic pattern of genetic alterations was found in ETPs. In both, the amount of chromosomal aberrations correlated with tumor size. In small ETPs and JGCTs, genetic losses dominated over gains of chromosomes, whereas in large/malignant ETPs, gains and losses were equally affected. Thus, JGCTs represent a special type of renal endocrine neoplasm characterized by deregulation of cell cycle components and a typical profile of chromosomal aberrations. Since only two JCTs were investigated, further studies for validation of these results are, however, necessary.

p53 and MDM2 in renal cell carcinoma: biomarkers for disease progression and future therapeutic targets?

Renal cell carcinoma (RCC) is the most common type of kidney cancer and follows an unpredictable disease course. To improve prognostication, a better understanding of critical genes associated with disease progression is required. The objective of this review was to focus attention on 2 such genes, p53 and murine double minute 2 (MDM2), and to provide a comprehensive summary and critical analysis of the literature regarding these genes in RCC. Information was compiled by searching the PubMed database for articles that were published or e-published up to April 1, 2009. Search terms included renal cancer, renal cell carcinoma, p53, and MDM2. Full articles and any supplementary data were examined; and, when appropriate, references were checked for additional material. All studies that described assessment of p53 and/or MDM2 in renal cancer were included. The authors concluded that increased p53 expression, but not p53 mutation, is associated with reduced overall survival/more rapid disease progression in RCC. There also was evidence that MDM2 up-regulation is associated with decreased disease-specific survival. Two features of RCC stood out as unusual and will require further investigation. First, increased p53 expression is tightly linked with increased MDM2 expression; and, second, patients who have tumors that display increased p53 and MDM2 expression may have the poorest overall survival. Because there was no evidence to support the conclusion that p53 mutation is associated with poorer survival, it seemed clear that increased p53 expression in RCC occurs independent of mutation. Further investigation of the mechanisms leading to increased p53/MDM2 expression in RCC may lead to improved prognostication and to the identification of novel therapeutic interventions.

Expression of CD44 protein in renal cell carcinomas: association with p53 expression

CD44 is an adhesion molecule involved in cell-to-cell and cell-to-matrix interactions. Recent evidence indicates a role of CD44 in tumor growth and metastatic potential of tumor cells. Moreover, it is widely known that the p53 tumor suppressor gene controls cell proliferation and loss of its normal function may lead to carcinogenesis. To investigate the role of these biomarkers in renal cancer, we analyzed the immunohistochemical distribution of CD44's expression on formalin fixed paraffin embedded tissue from 67 renal cell carcinomas and correlated with clinicopathologic parameters as well as with p53 suppressor gene expression. The monoclonal antibodies CD44 and p53 were applied to the tissues using the streptavidin biotin peroxidase method after microwave antigen retrieval. For CD44 and p53 more than 10% membranous and 5% nuclear staining, respectively, were estimated as positive. CD44's membranous immunoreactivity was detected in 24/67 tumors (35%) and mostly in carcinomas of clear/granular cell type. Nine tumors expressed nuclear immunoexpression of p53 protein (13.4%). Statistically significant correlation was noted between CD44 expression and nuclear grade (P < 0.001), tumor stage (P < 0.001), vascular invasion (P < 0.05) and p53 expression (P < 0.01). These results suggest that CD44s and p53 are markers of tumor progression in renal cell cancer.

The significance of p53 mutations as an indicator of the biological behavior of recurrent hepatocellular carcinomas

The significance of p53 mutations in the primary lesion for recurrent hepatocellular carcinoma (HCC) was evaluated. Mutations of p53 were examined using nonradioisotopic (nonRI)-polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) in 98 resected HCCs. Of the 98 cases, 25 (26%) had a p53 mutation. In 83 patients who survived surgery, the presence of a p53 mutation was associated with a shortened overall survival (P < 0.001) and a shortened cancer-free survival (P < 0.05). In 43 patients who developed recurrence, there was no statistically significant correlation between the status of p53 in the primary lesion and the clinical features of recurrent HCCs examined, i.e., extrahepatic metastasis, the number of recurrent tumors, extent of recurrent tumors, and treatment for recurrent tumors. However, postrecurrence survival was significantly lower in patients in whom a p53 mutation had been detected in the primary lesion (P < 0.01). A multivariate analysis for prognostic value after recurrence revealed that the p53 mutation was a useful independent prognostic factor affecting survival after recurrence (P < 0.01). In conclusion, our findings suggest that HCCs with p53 mutations have a high malignant potential based on their poor prognosis. Therefore, a p53 mutation in the primary lesion is useful as an indicator of the biological behavior of recurrent HCCs.

Renal neoplasias in patients receiving dialysis and renal transplantation: clinico-pathological features and p53 gene mutations

BACKGROUND

In Japan, the relative risk for renal cell carcinoma (RCC) in renal transplants was about 80-fold higher than that in the general population. Depressed immune surveillance due to the use of immunosuppressive agents was considered to cause cancer. Before renal transplantation, a vast majority of patients received hemodialysis, a known causative factor for acquired cystic disease of kidney (ACDK). Because ACDK is also considered to predispose to RCC, at least two risk factors for cancer accumulate in renal transplants.

METHODS

In our study, clinicopathological features together with p53 gene mutations were analyzed in 218 patients with RCC: 22 received dialysis followed by renal transplantation, 39 received dialysis alone, and 157 sporadic RCC. P53 mutations were analyzed on DNA extracted from paraffin-embedded specimens with use of single strand conformation polymorphism, followed by direct sequencing.

RESULTS

RCC in transplants shared several clinicopathological features with those in dialysis patients, which included small size and multiplicity of tumor, relatively high frequency of presence of ACDK, and papillary type of RCC. p53 gene mutations were infrequent in RCC of any clinical setting.

CONCLUSIONS

Atrophic kidney at the end-stage of renal failure and under dialysis have lesions of ACDK that might predispose to RCC in dialysis and transplant patients.

Nuclear p53 overexpression in bladder, prostate, and renal carcinomas

BACKGROUND

The aim of this study was to examine nuclear p53 overexpression in transitional cell carcinoma of the bladder, adenocarcinoma of the prostate, and renal cell carcinoma.

METHODS

Forty-four pathologic specimens from 39 bladder cancer patients, 41 prostatic adenocarcinoma, and 39 renal cell carcinoma specimens were analyzed immunohistochemically with D07 monoclonal antibody to detect the expression of the mutant p53 gene. Overexpression was said to occur when the number of positively-stained tumor nuclei were > or = 10% in each specimen. p53 overexpression was correlated with the clinical and histopathological features of these cancers.

RESULTS

Nuclear p53 overexpression occurred in 18.2% of transitional cell bladder cancer specimens, 12.2% of prostate cancer specimens, and 17.9% of renal cell cancer specimens. Statistical analyses showed that grade, vascular invasion, and necrosis in bladder cancer, a high Gleason score in prostate cancer, and the 1-year mortality rate in renal cancer were significantly related with p53 nuclear overexpression (P < 0.05).

CONCLUSION

Using the D07 monoclonal antibody, nuclear p53 overexpression is relatively uncommon in urologic malignancies, and moderately correlates with several histopathological and clinical features of urologic malignancies.

Renal cell carcinoma

Renal cell carcinoma (RCC) is characterized by (a) lack of early warning signs, which results in a high proportion of patients with metastases at the time of diagnosis; (b) protean clinical manifestations; and (c) resistance to radiotherapy and chemotherapy. The estimates of new diagnoses and deaths from kidney cancer in the United States during 1996 are 30,600 and 12,000, respectively. RCC occurs nearly twice as often in men as in women. The age at diagnosis is generally older than 40 years; the median age is in the midsixties. The incidence of RCC has been rising steadily. Between 1974 and 1990, there was a 38% increase in the number of patients who had a diagnosis of RCC. This increase was accompanied by a significant improvement in 5-year survival. Both trends are likely the result of improved diagnostic capability. Newer radiographic techniques, including ultrasonography, computed tomography, and magnetic resonance imaging, are detecting kidney tumors more frequently and at a lower disease stage, when tumors can be resected for cure. Surgical treatment is the only curative therapy for localized RCC. Radical nephrectomy remains the mainstay of surgical management, but techniques are being modified. These modifications include partial nephrectomy and resection of vena caval thrombi. In highly selected cases, surgical resection of locally recurrent RCC or of disease at a solitary metastatic site is associated with long-term survival. Metastatic RCC is highly resistant to the many systemic therapies that have been extensively investigated. A minority of patients achieve complete or partial response to interferon, interleukin-2, or both. Response can be dramatic but is rarely durable. Because most patients do not achieve response, these agents are not considered effective treatments for RCC, but the response in some patients indicates the need for continued research on their use. Identification of new agents with better antitumor activity against metastases remains a high priority in clinical investigation of therapy for this refractory disease.

Expression and sequence analysis of the p21(WAF1/CIP1) gene in renal cancers

OBJECTIVES

The p21(WAF1/CIP1) cyclin-dependent kinase inhibitor is an Mr 21,000 protein that can arrest cell growth by associating with and inhibiting cyclin-dependent kinase complexes necessary for cells to exit G1. It is a downstream effector in the p53 growth control pathway and can be transcriptionally activated by increasing levels of p53 protein. The objective of this study was to determine if there are mutations or alterations in the expression of p21 in renal cancers that could contribute to renal cancer cell growth.

METHODS

Twelve renal cancer cell lines were examined for mutations in the coding region of the p21 gene using single-stranded conformation polymorphism analysis and direct deoxyribonucleic acid (DNA) sequencing. Expression of p21 was determined in all 12 cell lines by Northern analysis using a cDNA probe for p21 and Western analyses using a p21-specific antibody.

RESULTS

Nucleotide base substitutions were detected in the p21 gene in two cell lines, which did not result in amino acid substitutions. P21-specific mRNA was present in 8 of 12 renal cancer cell lines, as determined by Northern analysis, although p21 transcripts could be detected by polymerase chain reaction in all 12 renal cancers. Varying levels of p21-specific protein were detected in 9 of 12 renal cancers.

CONCLUSIONS

These data indicate that mutation of the p21 gene is rare in renal cancer cell lines and that the uncontrolled growth of renal cancer cells is not due to mutation of the p21 gene. However, expression studies found a wide variation in the level of p21 protein in renal cancer cells, suggesting that aberrant regulation of p21 expression may play a role in renal cancer development.

Mutation of the p53 tumour suppressor gene occurs preferentially in the chromophobe type of renal cell tumour

Genomic DNA from 30 non-papillary and 20 chromophobe renal cell carcinomas (RCCs), 30 papillary renal cell tumours, and 20 renal oncocytomas was screened for the presence of mutations in exons 5-8 of the p53 tumour suppressor gene by polymerase chain reaction-single strand conformation polymorphism analysis and direct DNA sequencing. Mutations leading to an amino acid change were found only in 6 out 20 chromophobe RCCs. Microsatellite analysis of chromophobe RCCs revealed the loss of one allele at chromosome 17p in 14 out of 18 informative cases. No mutation of the p53 gene was found in five sarcomatous RCCs or in seven tumours of stage IV. This study shows that mutation of the p53 tumour suppressor gene does not correlate with the specific loss of DNA sequences at chromosome 17 in chromophobe RCCs, nor can it be used as a prognostic parameter for RCCs in general.

p53 expression in odontogenic keratocyst epithelium

The expression of p53 protein was studied in odontogenic keratocysts (OKC, 11 solitary, 5 recurrent and 6 NBCCS cysts), radicular (RC, n = 5) and dentigerous (DC, n = 5) cysts, using a panel of antibodies to p53 (clone BP53-12, clone 1801 and polyclonal CM1) and a sensitive biotin-streptavidin method on paraffin embedded sections. Of the three antibodies tested, clone BP53-12 gave the most intense and consistent nuclear staining pattern. Clone 1801 and polyclonal CM1 stained only 38% and 71% OKC linings, respectively, but not RC and DC linings. However, BP53-12+ cells were detected in the epithelial linings of all cyst types. Quantification of BP53-12+ cells was performed by manual counting and by relating cell number to unit length of basement membrane as determined by TV image analysis. BP53-12+ cell counts in solitary OKC linings (25.5 +/- 11.0 cells/mmBM) were significantly greater than those in DC (9.3 +/- 4.9 cells/mmBM, P < 0.01) and RC (6.7 +/- 2.6 cells/mmBM, P < 0.01) linings. The epithelial distribution of positive cells in OKC was predominantly suprabasal, which also varied from that of DC and RC linings (P < 0.005). There were no detectable differences in BP53-12 reactivity between the different subtypes of OKC (i.e., solitary, recurrent and NBCCS-associated OKC; P > 0.1). When data for the NBCCS-related OKC group were excluded, there was a significant correlation (r = 0.55, P < 0.01) between p53 and Ki67 labelling. To detect the presence of p53 gene mutations, genomic DNA, extracted from paraffin sections of OKC (4 solitary, 2 recurrent and 4 NBCCS cysts), RC (n = 3) and normal oral mucosa (n = 1), was subjected to a combination of polymerase chain reaction and single-stranded conformation polymorphism (PCR-SSCP) analysis for exons 5-10 of the p53 gene. Exon 4 was not analysed because of compromised DNA quality. No abnormality in banding patterns was found and all samples gave results similar to DNA from known, sequenced, normal p53 gene controls. Absence of p53 mutations within exons 5-9 was confirmed by the direct sequencing of 2 fresh frozen OKC samples (1 solitary and 1 NBCCS cyst). These results suggest that overexpression of p53 protein in OKC epithelium, detected by immunocytochemistry, is not reflected by alteration of the p53 gene and presumably reflects overproduction and/or stabilisation of normal p53 protein.

Low incidence of point mutations in H-, K- and N-ras oncogenes and p53 tumor suppressor gene in renal cell carcinoma and peritoneal mesothelioma of Wistar rats induced by ferric nitrilotriacetate

An iron chelate, ferric nitrilotriacetate (Fe-NTA, induces renal proximal tubular damage, a consequence of iron-catalyzed free radical reactions, that finally leads to a high incidence of renal cell carcinoma (RCC) in rodents. Previous studies have identified, within 24 h after administration of Fe-NTA, lipid peroxidation products, aldehyde-modified proteins and a variety of modified DNA bases such as 8-hydroxyguanine that may be mutagenic in vivo. In the present study, pathological features of the RCCs were studied, and, in an effort to correlate them with carcinogen-specific molecular events in Fe-NTA-induced carcinogenesis, the H-, K- and N-ras oncogenes and the p53 tumor suppressor gene were investigated for the presence of mutations. Fe-NTA-induced RCCs showed similarity to human RCCs in that they are often invasive, metastatic and fatal. None (0 of 12) of the tumors had mutation in codons 12, 13 and 61 of the H-, K- and N-ras genes by direct sequencing. Only one (1 of 12) tumor with high grade histology revealed a CGC-to-CTC (Arg to Leu) transversion in codon 246 of the p53 gene by the use of single strand conformation polymorphism (SSCP) analysis and direct sequencing. High expression of mutant p53 protein was confirmed by Western blotting and immunohistochemistry. Study of three peritoneal mesotheliomas induced by Fe-NTA revealed no mutation in ras and p53 genes. These results suggest that the ras and p53 genes are not the major targets of mutation in Fe-NTA-induced carcinogenesis of kidney and mesothelium. Instead, p53 mutation may work for potentiation of malignant character in Fe-NTA-induced renal carcinogenesis.