Distinctive chromosomal instability patterns in oral verrucous and squamous cell carcinomas detected by high-resolution DNA flow cytometry

BACKGROUND:

Oral verrucous carcinomas (OVCs) are characterized by better prognosis than oral squamous cell carcinomas (OSCCs). Because chromosomal instability (CIN) in solid tumors is indicative of prognosis, this study investigated whether OVCs and OSCCs were characterized by differences in CIN biomarkers.

METHODS:

Fresh or frozen multiple tissue samples were submitted to high‐resolution DNA flow cytometry (hr DNA‐FCM).

RESULTS:

DNA aneuploid sublines were detected in 6 of 9 OVCs (66.7%) and in 20 of 25 OSCCs (80.0%). Multiple DNA aneuploid sublines were observed, respectively, in 2 of 6 (33.3%) DNA aneuploid OVCs and in 14 of 20 (70%) DNA aneuploid OSCCs (P = .163). OVCs were mainly characterized by DNA Index (DI) values in the near‐diploid region (DI≠1 and DI < 1.4), whereas aneuploid OSCCs carried most frequently multiple aneuploid sublines with high DI values (DI ≥ 1.4). DNA near‐diploid and high aneuploid sublines were, respectively, 87.5% and 12.5% for the OVCs versus 30% and 70% for the OSCCs (P = .004).

CONCLUSIONS:

Present data suggest that OVCs are characterized by a lower degree of CIN and tumor heterogeneity than OSCCs, such that they appear as “frozen” in an early stage of DNA near‐diploid aneuploidy, as previously observed for oral preneoplastic lesions. These DI characteristics, which can easily be obtained by hr DNA‐FCM, appear to reflect the well‐known differences in aggressiveness and prognosis of OVCs and OSCCs. Cancer 2011;. © 2011 American Cancer Society.     

p53 mutations, protein expression and cell proliferation in squamous cell carcinomas of the head and neck.

Thirty-three patients with squamous cell carcinoma of the head and neck region were studied concerning p53 protein expression and mutations in exons 4-9 of the p53 gene using immunohistochemistry, polymerase chain reaction (PCR)-single strand conformation polymorphism analysis and DNA sequencing. Immunoreactivity was found in 64% and p53 gene mutations in 39% of the tumours. Thirty-three per cent of the immunopositive and 50% of the immunonegative tumours were mutated within exons 5-8. In one immunopositive tumour three variants of deletions were observed. Sequencing of the p53 mutated, immunonegative tumours revealed four cases with deletions, one case with a transversion resulting in a stop codon and one case with a splice site mutation which could result in omission of the following exon at splicing. All mutations in the immunonegative tumours resulted in a truncated p53 protein. No association between p53 gene status and expression of proliferating cell nuclear antigen (PCNA) or cell proliferation as judged by in vivo incorporation of the thymidine analogue iododeoxyuridine (IdUrd) was found.     

Dual-parameter flow cytometry of transitional cell carcinomas. Quantitation of DNA content and binding of carbohydrate ligands in cellular subpopulations

Quantitative DNA measurements and estimates of blood group-related carbohydrate antigen expression have been used as predictive parameters in transitional cell carcinomas (Ca). To obtain an accurate quantitative characterization of cellular subpopulations on the basis of these parameters, the authors developed a dual-parameter flow cytometric method using a fluorescence-activated cell sorter. With this method single-cell suspensions from 26 transitional cell carcinomas were analyzed by means of propidium iodide (red fluorescence) as DNA ligand, and peanut agglutinin (PNA), wheat germ agglutinin (WGA), and anti-blood group A antibody (aBGA) as carbohydrate ligands. The latter ligands were visualized directly or indirectly by FITC (green fluorescence). The carbohydrate ligand binding was correlated to the DNA content of cell populations in the way that aneuploid populations showed a higher PNA binding (P less than 0.0002) and a lower WGA (P less than 0.01) and aBGA (P less than 0.04) binding than did diploid cell populations. The binding of PNA to aneuploid populations could be further increased (P less than 0.004) by neuraminidase treatments. Thus, aneuploid cells express both neuraminic acid substituted and unsubstituted PNA receptors. The carbohydrate ligand binding was cell cycle-dependent, as it was reduced (less than 0.008) in the G2-M phase. A low WGA (P less than 0.004) or aBGA (P less than 0.02) binding was correlated to tissue invasion. Immunohistochemistry with the carbohydrate ligands showed a good correlation between aBGA (P less than 0.0005) and PNA (P less than 0.004) binding to tumor cells and flow cytometric assay of these, as well as a correlation (P less than 0.003) between cellular location of WGA receptors and flow cytometric assay of these. It seems that dual-parameter flow cytometry represents an important tool in the characterization of bladder tumors.     

Jun activation domain-binding protein 1 expression in oral squamous cell carcinomas inversely correlates with the cell cycle inhibitor p27

The Jun activation domain-binding protein 1 (Jab1) may be involved in degradation of the cyclin-dependent kinase inhibitor p27, but it has not been clarified. In this study, we observed expression levels of Jab1 and p27 in oral squamous cell carcinoma (OSCC) and normal oral mucosa tissue and evaluated whether the Jab1 expression is correlated with p27 protein levels and how it is clinically relevant OSCC. The clinicopathological features and immunohistochemical expression levels of Jab1 and p27 proteins were immunohistochemically studied in 206 specimens from patients who underwent surgical resection for OSCC. Survival analyses were performed by using the Kaplan-Meier method. Jab1 overexpression was detected in 83% (171 of 206) of OSCCs and 19% (4 of 21) of normal oral mucosa. While p27 expression was 60% in OSCCs. We found an inverse correlation between Jab1 and p27 expression levels (P?相似文献   

Mutation of p53 gene codon 63 in saliva as a molecular marker for oral squamous cell carcinomas

The inactivation of tumor suppressor gene (TSG) is important during multistage carcinogenesis. The p53 TSG is frequently mutated in oral squamous cell carcinomas. These mutations can serve as very specific markers for the presence of tumor cells in a background of normal cells. In this study, 10 oral squamous cell carcinoma patients and 27 normal dental students were collected from Chung Shan Medical and Dental College Hospital, Taichung, Taiwan. Extractions of DNA from saliva were obtained. Exon 4 and intron 6 within the p53 gene were amplified with polymerase chain reactions (PCRs) followed by DNA sequence analysis. DNA sequence analysis of PCR products revealed that five of eight (62.5%) tumor saliva samples and five of 27 (18. 52%) healthy saliva samples contained p53 exon 4 codon 63 mutations. These results were significantly different by using Chi-square test (P<0.05). The majority of the base substitutions were C deletions. Probable hot spots for the mutation were identified at exon 4 codon 63, which has not been observed before in head and neck cancers. Our study indicated that mutation of p53 codon 63 in saliva might be a molecular marker for oral squamous cell carcinomas. In addition, the amount of DNA recovered from saliva in most cases is sufficiently large and its quality suitable to enable PCR amplification which could be used in the search for mutations. The protocol described is rapid, cheap, and easy to perform, and may be useful for epidemiological studies for oral carcinogenesis.     

Protein microarray analysis of apoptosis-related protein expression following heat shock in human tongue squamous cell carcinomas containing different p53 phenotypes

Purpose: Hyperthermia is useful in the treatment of human head and neck cancers, because it is relatively easy to regulate temperatures when compared to tumors located in deep organs. In this study, attention was focused on p53 as a possible predictive indicator for the efficacy of hyperthermic cancer therapy.

Methods: Two kinds of cell lines were used. These were derived from a human squamous cell carcinoma (SAS) and had identical genetic backgrounds except for their p53 gene status. It was previously reported that the heat sensitivity and frequency of apoptosis in wild-type p53 cells (SAS/neo) were clearly elevated when compared with mutated p53 cells (SAS/mp53). In order to study the expression of apoptosis related proteins after heat treatment, protein microarray analysis was used.

Results: The expression of apoptosis inhibitory proteins such as Bcl-2, Bcl-xL, NF-κB, COX2, STAT3, IL-6, and IKKα/1 was seen to increase after heat treatment in SAS/mp53 cells, but not in SAS/neo cells.

Conclusion: The result of these observations indicates that apoptosis inhibitory proteins (such as Bcl-2, Bcl-xL, IL-6, etc.) were highly induced in SAS/mp53 cells after heat treatment when compared to control SAS/neo cells.     

Lack of prognostic significance for p53-overexpression and Ki-67-immunoreactivity in oral T1-2 squamous cell carcinomas

Previous investigations on squamous cell carcinomas (SCC) of the head and neck region have failed to reveal a significant correlation between p53-overexpression or Ki-67-immunoreactivity and survival. Contrary to these studies we restricted the evaluation to T1-2 SCC from the oral cavity. Immunohistochemically identified p53-overexpression was observed in 69% of the tumours, and Ki-67-positive cancer cells ranged from 12 to 83% in individual rumours (median 37%). No significant correlation was found between p53-overexpression or Ki-67-positivity and survival. Although the degree of tumour differentiation and the pattern of invasion correlated with prognosis (p=0.0387 and 0.0319 respectively), these associations were too weak to be used as prognostic markers.     

Diffuse mode of tumor cell invasion and expression of mutant p53 protein but not of p21 protein are correlated with treatment failure in oral carcinomas and their metastatic foci

Lack of control of metastatic foci is the most prevalent cause of death in patients with oral carcinomas, and it is important for tumor control to identify the factors that predispose patients to death. In the present study, we examined 225 patients with oral squamous cell carcinoma and investigated the immunohistopathological characteristics of 43 tumors that led to death, comparing them with those of the non-lethal tumors. In the 43 patients, lack of control of the primary site, lymph node and distant metastatic tumors were noted in 20, 18 and 16 patients, respectively. The mode of tumor cell invasion was closely correlated with death. The diffuse invasion modes of grades 4C and 4D were observed in 15 (34.9%) of the 43 tumors with a poor outcome and in 35 (19.2%) of the 182 controlled tumors (p < 0.02). The expression of p53 was highly correlated with death. Of the tumors with poor prognosis, p53 protein was expressed in 32 tumors (76.2%). However, p53 protein expression was observed in 52.7% of the tumors with good prognosis (p < 0.02). In contrast, the expression of p21 protein in the well-controlled tumors (30.4%) was almost equal to that of the 43 lethal tumors (26.2%). Compared with the ratios of local recurrence, metastases and their treatment failures in the p53-negative grade 1 and 2 tumors, those in the mutant p53-positive grade 3, 4C and 4D tumors were mostly high. These results indicate that measuring p53 protein expression and evaluating the mode of tumor cell invasion are important for oral carcinoma therapy because the expression of mutant p53 protein and the diffuse modes of tumor cell invasion indicate a predisposition toward a poor prognosis.     

p53 and cyclin D1 protein expression in glottic laryngeal squamous cell carcinomas involving the anterior commissure (pT1bN0M0)

The prognosis of patients carrying glottic squamous cell carcinomas (GSCCs) involving the anterior commissure is often unpredictable. In order to assess the possible prognostic role of new and reliable parameters, p53 and cyclin D1 protein expression was immunohistochemically analysed in pathological samples from 27 patients with GSCG (pTlbNOMO) and a median follow-up of 90 months. p53 protein expression was observed in the majority of patients (15/27), but it did not correlate with their clinical outcome; p53 protein immunoreactivity was frequently observed in normal (9/14), mildy dysplastic (10/14) and highly dysplastic (3/7) mucosa samples, suggesting that its overexpression may be involved in the earliest phases of the multistep tumourigenesis of laryngeal squamous cell carcinomas (LSCCs); neither the non-neoplastic nor the neoplastic samples expressed any cyclin D1. As cyclin D1 protein expression has been associated with a high frequency of nodal metastases, its absence in our series could ba related to the rarity of nodal involvement in early glottic LSCCs.     

Correlations among p53, Her-2/neu, and ras overexpression and aneuploidy by multiparameter flow cytometry in human breast cancer: evidence for a common phenotypic evolutionary pattern in infiltrating ductal carcinomas.

Human solid tumors develop multiple genetic abnormalities that accumulate progressively in individual cells during the course of tumor evolution. We sought to determine whether there are specific sequences of occurrence of these progressive evolutionary changes in human breast cancers by performing correlated cell-by-cell measurements of cell DNA content, p53 protein, Her-2/neu protein, and ras protein by multiparameter flow cytometry in 56 primary tumor samples obtained at surgery. In addition, p53 allelic loss and Her-2/neu gene amplification were determined by fluorescence in situ hybridization in cells from the same samples. We reasoned that if there is a specific order in which genetic changes occur, the same early changes would be found consistently in the cells with the fewest abnormalities. We reasoned further that late-developing abnormalities would not occur alone in individual cells but would almost always be found together with the early changes inherited by the same cells. By these criteria, abnormalities involving p53 generally occurred early in the course of development of invasive breast cancers, whereas ras protein overexpression was found to be a late-occurring phenomenon. Within individual tumors, cellular p53 overexpression was often observed alone in individual cells, whereas ras protein overexpression was rarely observed in the absence of p53 overexpression and/or Her-2/neu overexpression in the same cells. Furthermore, the intracellular level of each abnormally expressed protein was found to increase progressively as new abnormalities were acquired. Infiltrating ductal carcinomas exhibited characteristic phenotypic patterns in which p53 allelic loss and/or p53 protein overexpression, Her-2/neu amplification and/or overexpression, aneuploidy, and ras overexpression accumulated within individual cells. However, this pattern was not a prominent feature of lobular breast cancers. All six lobular breast cancers studied were diploid. p53 allelic loss and/or early p53 overexpression, and late ras cooverexpression in the same cells were less common in lobular breast cancers than in infiltrating ductal carcinomas. Although Her-21neu overexpression was a common finding in lobular breast cancers, Her-2/neu amplification was not observed in these tumors.