p53 protein expression in malignant, pre-malignant and non-malignant lesions of the lip

A short review on DNA damage and repair effects in lip cancer

Increasing trend in oral cancer (0.6% per year) and its related mortality has been reported worldwide since 2010. The United States alone reports an increase of 57% within the past 10 years. This emphasizes the need not only for designing strategies of prevention and planning but also for an effective treatment regime for the various oral cancers. Cancers of the lips, tongue, cheeks, floor of the mouth, and hard palate have been primarily classified under the category of oral cancers. If left undiagnosed, these cancers can be life threatening. Amongst these, the most undesignated and understudied cancer type is the lip carcinoma, which is either categorized under oral cancer or/as well as skin cancer or head and neck cancer. However, lip cancer corresponds to 25-30% of all diagnosed oral cancers. Though the etiology of lip cancer is not yet fully understood, numerous risk factors involved in its development are now being studied. The cells in the lip region are continuously exposed to various DNA damaging agents from endogenous as well as exogenous sources. Flaws in DNA repair mechanisms involved in eliminating these damages may be linked to the origin of carcinogenesis. Accumulation of DNA damage and defect in repair mechanisms may play a role in lip carcinogenesis and progression. This literature review is an exhaustive compilation of the research work performed on the role of DNA damage and repair responses in lip carcinoma which will pave a path for researchers to identify predictive DNA repair biomarker/s for lip cancer, and its diagnosis, prevention, and treatment.

Immunohistochemical analysis of epithelium adjacent to lip cancer: A meta-analysis

OBJECTIVES

To identify the immunohistochemical pattern of non-tumoral epithelium adjacent to lip cancer (ANTE) to unveil molecular alterations and potential biomarkers in lip cancer patients.

MATERIALS AND METHODS

A systematic search at MEDLINE, EMBASE and proceedings Web of Science, OpenGrey and WorldCat. The PICOS outline (Population: lip cancer patients; Intervention: immunostaining with biomarkers in surgical specimens; Comparisons: ANTE versus LC; Outcomes: primary-to identify the immunohistochemical pattern of peritumoral epithelium and secondary-to assess the immunoreactivity of LC epithelium; and Study design: cross-sectional, case-control and cohort studies).

RESULTS

A total of 339 records were identified. Seven studies reporting on ANTE and LCs were included in the qualitative synthesis, and 4 of them (p53 immunostaining) were selected for meta-analysis. In the ANTE group, the pooled prevalence of p53 was 0.74 (95% CI: 0.66 - 0.82), while in the lip squamous cell carcinoma group this prevalence was 0.83 (95% CI: 0.75 - 0.89).

CONCLUSIONS

Similar immunoexpression was found in lip epithelium adjacent to lip carcinoma, even in epithelia with normal appearance or mild histological alterations. The role of biomarkers in the follow-up of actinic cheilitis patients deserves additional clinical assessment.

Markers of Oral Lichen Planus Malignant Transformation

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology with significant impact on patients' quality of life. Malignant transformation into oral squamous cell carcinoma (OSCC) is considered as one of the most serious complications of the disease; nevertheless, controversy still persists. Various factors seem to be involved in the progression of malignant transformation; however, the mechanism of this process is not fully understood yet. Molecular alterations detected in OLP samples might represent useful biomarkers for predicting and monitoring the malignant progression. In this review, we discuss various studies which highlight different molecules as ominous predictors of OLP malignant transformation.

New Approaches To the Understanding of the Molecular Basis of Oral Cancer

Cancers of the oral cavity, salivary glands, larynx, and pharynx, collectively referred to as squamous cell carcinomas of the head and neck (HNSCC), are the sixth most common cancer among men in the developed world. The prognosis of HNSCC patients is still poor, which reflects the fact that although the risk factors for HNSCC are well-recognized, very little is known about the molecular mechanisms responsible for this malignancy. This review describes some of the current efforts and technological advances that have focused on the creation of a complete information infrastructure for genes expressed during squamous cell carcinogenesis. These include: the recently described HNSCC-specific chromosomal alterations (cCAP); the Head and Neck Cancer Genome Anatomy Project (HN-CGAP), whose goal is the systematic identification and cataloguing of known and novel genes expressed during tumor development; and the use of laser-capture microdissection (LCM), which is pivotal for the comprehensive molecular characterization of normal, pre-cancerous, and malignant cells by means of DNA-array technology. The latter provides the means for the analysis of expression patterns of thousands of genes simultaneously. The use of LCM for proteomics and DNA analysis is also included in this review. These revolutionary approaches are likely to have an unprecedented impact on cancer biology, and provide exciting opportunities to unravel the still-unknown mechanisms involved in squamous cell carcinogenesis. They are also expected to provide a molecular blueprint for HNSCC, thus helping to identify suitable markers for the early detection of pre-neoplastic lesions, as well as novel targets for pharmacological intervention in this disease.

KAI-1 and p53 expression in oral squamous cell carcinomas: Markers of significance in future diagnostics and possibly therapeutics

CONTEXT

KAI-1/CD82 is a tumor suppressor gene with decreased gene expression being associated with increased invasive ability of oral squamous cell carcinomas (OSCCs). p53 protein functions in the G1-S phase of the cell cycle to allow repair of damaged DNA. In the present study, p53 and KAI-1 expression was investigated using monoclonal antibodies in OSCC.

AIMS

The aim of this study was to detect KAI-1 and p53 expression in OSCCs and to assess the relation between both in OSCCs.

MATERIALS AND METHODS

The present study included histopathologically diagnosed thirty cases of well- and moderately differentiated OSCCs to study the expression of KAI-1 and p53 antibodies.

STATISTICAL ANALYSIS

The results obtained were tabulated and statistically analyzed using descriptive statistical analysis; one-way ANOVA; least square difference method and independent t-test.

RESULTS

OSCCs exhibited 41.62% positivity for KAI-1 while p53 positive cells were recorded to an extent of 60.82%. A significant positive correlation was observed between KAI-1 and p53 expression in OSCCs.

CONCLUSIONS

Although a significant amount of work is still required to uncover the mechanisms of action and regulation of KAI-1 and p53 expression, control of the complex metastatic processes would be of interest in controlling the tumor biology in OSCCs as well as other types of malignancies to enhance prognosis in the affected patients and to help protect against future metastasis in the going to be treated and treated patients.

High azathioprine dose and lip cancer risk in liver, heart, and lung transplant recipients: A population-based cohort study

BACKGROUND

Iatrogenic immunosuppression is a risk factor for lip cancer but the determinants are unknown.

OBJECTIVE

We sought to quantify the association between the type, dose, and duration of iatrogenic immunosuppression and lip cancer risk in solid organ transplant recipients.

METHODS

We conducted a population-based cohort study of all adult Australian liver, heart, and lung transplant recipients from 1984 to 2006 (n = 4141). We abstracted longitudinal data from medical records and ascertained incident lip cancer (n = 58) and deaths (n = 1434) by linkage with national registries. We estimated multivariable hazard ratios (HR) for lip cancer using the Fine and Gray proportional subdistribution hazards model, accounting for death as a competing risk.

RESULTS

Lip cancer risk (n = 58) increased with high mean daily dose of azathioprine (HR 2.28, 95% confidence interval [CI] 1.18-4.38), longer duration of immunosuppression (HR 9.86, 95% CI 2.10-46.3), increasing year of age at transplantation (HR 1.14, 95% CI 1.04-1.25), earlier transplantation era (HR 8.73, 95% CI 1.11-68.7), and history of smoking (HR 2.71, 95% CI 1.09-6.70).

LIMITATIONS

Data on potential confounders such as personal solar ultraviolet radiation exposure were not available.

CONCLUSION

Higher doses of azathioprine increase lip cancer risk, with implications for managing immunosuppressed populations and our understanding of the relationship between solar ultraviolet radiation and lip cancer.

Global DNA methylation: uncommon event in oral lichenoid disease

OBJECTIVES

Accumulating evidence indicates that aberrant DNA methylation is closely related to oral carcinogenesis, and it has been shown that methylation changes might be used as prognostic biomarker in oral squamous cell carcinoma. Oral lichenoid disease (OLD) is the most common oral potentially malignant disorder in our region. The aim of this study was to perform the first wide DNA methylation study in OLD in order to investigate the relevance of DNA methylation changes in this premalignant disorder.

MATERIALS AND METHODS

Two different Illumina microarray platforms, namely the GoldenGate Cancer Panel I and the HumanMethylation27 DNA Analysis BeadChip, were utilized in the discovery phase to interrogate the methylation profile of 59 OLD cases and 9 healthy individuals. Top-ranked genes were further validated by pyrosequencing in a second sample set consisting of 160 OLD and 65 controls.

RESULTS

Our results show that the frequency of aberrant DNA methylation is rare in OLD, and this finding was further corroborated by pyrosequencing in the biological validation.

CONCLUSIONS

These findings reinforce the notion that molecular alterations associated with oral carcinogenesis do not seem to be common events in OLD, which in turn might explain the low rate of malignization of this disorder.

Actinic cheilitis and squamous cell carcinoma of the lip: clinical, histopathological and immunogenetic aspects

Actinic cheilitis is the main precancerous lesion of the lip. Squamous cell carcinoma of the lip is reported together with oral carcinomas in the Brazilian official statistics. Overall, they account for 40% of the head and neck carcinomas. In general, physicians and dentists know little about what causes oral tumor development and progression. Tumor suppressor genes and cell proliferation regulatory proteins play a role in the progression of actinic cheilitis to squamous cell carcinoma and in its biological behavior. Knowledge on prognostic and diagnostic markers has a positive impact on the follow-up of these patients.

p53 and MDM2 protein expression in actinic cheilitis

Actinic cheilitis is a potentially malignant lip lesion caused by excessive and prolonged exposure to ultraviolet radiation, which can lead to histomorphological alterations indicative of abnormal cell differentiation. In this pathology, varying degrees of epithelial dysplasia may be found. There are few published studies regarding the p53 and MDM2 proteins in actinic cheilitis. Fifty-eight cases diagnosed with actinic cheilitis were histologically evaluated using Banóczy and Csiba (1976) parameters, and were subjected to immunohistochemical analysis using the streptavidin-biotin method in order to assess p53 and MDM2 protein expression. All studied cases expressed p53 proteins in basal and suprabasal layers. In the basal layer, the nuclei testing positive for p53 were stained intensely, while in the suprabasal layer, cells with slightly stained nuclei were predominant. All cases also tested positive for the MDM2 protein, but with varying degrees of nuclear expression and a predominance of slightly stained cells. A statistically significant correlation between the percentage of p53 and MDM2-positive cells was established, regardless of the degree of epithelial dysplasia. The expression of p53 and MDM2 proteins in actinic cheilitis can be an important indicator in lip carcinogenesis, regardless of the degree of epithelial dysplasia.

Bespoke human hypertrophic chondrocytic cell lines provide the osteoinductive signals required for vascularized bone formation

Hypertrophic cartilage provides the morphological and biochemical template for orchestrating bone growth. To produce a bone-inductive material such as hypertrophic cartilage for clinical use, we have conditionally immortalized hypertrophic chondrocytic cells from human femur and expanded them in vitro through more than 145 divisions. The clonal cell lines generated by this process consistently express signals that induce both rat and human marrow cells to differentiate in vitro into osteoblastic cells. Further, implantation of the cell-free extracellular matrix from the immortalized chondrocytic cells causes vascularized bone to form in vivo in bony defects, but not in ectopic sites such as skeletal muscle. This study shows that molecular techniques can be used to generate bespoke human cell lines for bone tissue engineering. It also demonstrates that matrix material generated from human immortalized hypertrophic chondrocytic cells may provide an abundant, efficacious, and safer alternative to bone autograft--the currently preferred material for fracture repair.

p53 and p21WAF1/CIP1 overexpression at the invasive front of lower lip squamous cell carcinoma

BACKGROUND

Lower lip squamous cell carcinoma (LLSCC) is an oral cancer that has distinct epidemiology and etiopathogenesis. Although risk factors for this neoplasia are acknowledged, few studies have investigated the molecular basis of its development and behavior.

METHODS

Expression of p53 and p21(WAF1/CIP1) was examined by immunohistochemistry of archived tissue from 21 specimens of LLSCC. Differences in this expression between the whole tumor (WT) and the invasive front (IF) as well as correlation between p53 and p21(WAF1/CIP1) expression were analyzed.

RESULTS

p53 and p21(WAF1/CIP1) were overexpressed at the IF of LLSCC. The expression of both proteins was higher at IF than at WT. No correlation was observed between p53 and p21(WAF1/CIP1) expression.

CONCLUSIONS

Our results indicate that p53 and p21(WAF1/CIP1) overexpression is important in LLSCC pathogenesis, reinforce that IF is the most important area for tumor behavior, and support that p53-independent mechanisms should be involved in the expression of p21(WAF1/CIP1).

Actinic cheilitis: histopathology and p53

BACKGROUND

Chronic actinic cheilitis (AC) is a precursor of squamous cell carcinoma (SCC) of the lip.

OBJECTIVES

To evaluate the histopathological characteristics that may help to identify AC more susceptible to carcinomatous transformation, to assess the p53 protein expression in AC, and to determine the value of the p53 expression as a marker of transformation into SCC of the lip.

METHODS

Seventy cases of chronic AC were reviewed, 31 of which were associated with SCCs. The samples were obtained from pathology reports of AC and SCC of the lip. Histopathology and immunohistochemical expression of the p53 protein were evaluated in isolated AC and in AC adjacent to SCC.

RESULTS

The intensity of the inflammatory infiltrate in the corium was the only histopathological finding significantly associated both with the presence of an invasive tumor and with the degree of epithelial atypia. Most AC (85%) were immunoreactive to the p53 protein. The p53 protein expression in cheilitis was not statistically associated with any other histopathological criteria.

CONCLUSIONS

An intense inflammatory infiltrate in AC was predictive of an adjacent invasive SCC. In this study, the p53 protein immunoreactivity was not a marker of malignant transformation.

Correlation between Bcl-2 and Bax in atrophic and hypertrophic type of actinic keratosis

BACKGROUND

Recent investigations consider actinic keratosis (AK) as an earliest visible pattern of squamous cell carcinoma (SCC). We have analysed the expression of apoptosis-related proteins TP53, Bcl-2 and Bax in 30 atrophic and 30 hypertrophic AK cases.

MATERIAL AND METHODS

Immunohistochemical analysis was performed following microwave streptavidin immunoperoxidase protocol on DAKO TechMate Horizon automated immunostainer (DAKO, Copenhagen, Denmark). Monoclonal antibody for TP53 and Bcl-2 and polyclonal antibody for Bax (DAKO, Copenhagen, Denmark) were used.

RESULTS

Expression of TP53 showed no significant differences between two analysed groups (chi2-test, P = 0.35636) whereas expression of Bcl-2 and Bax protein was significantly higher in atrophic compared to hypertrophic AK (chi2-test, P = 0.01458 and P = 0.00358, respectively). Comparison of Bcl-2 : Bax ratio in two analysed AK showed significantly higher value in hypertrophic compared to atrophic AK (Mann-Whitney U test, P = 0.02272). Statistical analysis did not show any correlation between patient's sex and age, localization and size of the lesion with expression of investigated oncoproteins (anova, P > 0.05).

CONCLUSIONS

Our results may indicate higher resistance of keratinocytes on apoptotic stimuli in hypertrophic compared to atrophic AK. Thus, we suppose that keratinocytes in hypertrophic AK live longer and probably have higher propensity for additional mutations and conversion to overt SCC.

Expression of apoptotic and cell proliferation regulatory proteins in actinic cheilitis

BACKGROUND

Actinic cheilitis (AC) is a pre-malignant lesion caused by ultraviolet (UV) radiation. The apoptotic proteins p53, bax, bcl-2, and the proliferation marker Ki-67, are known to play an important role in UV-exposed skin and carcinomas, therefore, these markers were assessed in AC and compared with normal lip and oral mucosa.

METHODS

AC (n = 13), normal lip (n = 7) and oral mucosa (n = 6) biopsies were stained immunohistochemically for p53, bax, bcl-2 and Ki-67, to determine their expression and distribution.

RESULTS

p53 was over-expressed in AC as compared with normal lip and oral mucosa (P < 0.003). Although bcl-2 expression was higher in AC than in oral mucosa (P < 0.002), it was significantly reduced as compared with normal lip (P < 0.04). Bax expression remained unchanged, and Ki-67 was significantly increased in AC and normal lip as compared with oral mucosa (P < 0.05).

CONCLUSION

The results suggest that DNA-damaged cells by UV radiation in AC are eliminated by apoptosis.

Analysis of p53 and bcl-2 protein expression in the non-tumorigenic, pretumorigenic, and tumorigenic keratinocytic hyperproliferative lesions

BACKGROUND

The hyperproliferative keratinocytic lesions encompass a wide range of non-tumorigenic, pretumorigenic, and tumorigenic conditions. The aim of this work was to examine the expression patterns of apoptosis-linked molecules (bcl-2 and p53) in these lesions.

METHODS

Immunoperoxidase staining methods were applied to analyze p53 and bcl-2 protein expression in a total of 66 cases, including 12 squamous cell carcinomas (both in situ and invasive SCC), 11 actinic keratoses (AK), 13 psoriasis vulgaris (PV), eight verruca vulgaris (VV), six chronic dermatitis (CD), five seborrheic keratosis (SK), four lichen planus (LP), three epidermodysplasia verruciformis (EDV), two condyloma acuminata (CA), two lichen simplex chronicus (LSC), and 10 specimens from normal skin.

RESULTS

As compared to normal skin (0.70 +/- 0.26), the bcl-2 average weighted scores in the non-tumorigenic (0.76 +/- 0.16), pretumorigenic (1.45 +/- 0.28), and tumorigenic lesions (2.83 +/- 0.50 and 2.92 +/- 0.50 for in situ and invasive SCC, respectively) showed significant up-regulation (p = 0.001). In the non-tumorigenic lesions, the bcl-2 expression values decreased in the following order: SK > EDV > CD > LP > CA > PV > VV (1.40 +/- 0.24 > 1.33 +/- 0.67 > 0.83 +/- 0.40 > 0.67 +/- 0.21 > 0.50 +/- 0.20 > 0.46 +/- 0.22 > 0.13 +/- 0.01, respectively). As compared to normal skin (1.10 +/- 0.23), the p53 average weighted scores in the non-tumorigenic (1.86 +/- 0.18), pretumorigenic (3.64 +/- 0.53), and tumorigenic lesions (5.00 +/- 1.00 and 5.08 +/- 0.86 for in situ and invasive SCC, respectively) showed significant up-regulation (p = 0.021). In the non-tumorigenic lesions, p53 average weighted scores decreased in the following order: SK > PV > CA > LP > CD > VV > EDV (3.20 +/- 0.49 > 2.38 +/- 0.27 > 2.0 +/- 0.0 > 1.83 +/- 0.48 > 1.0 +/- 0.37 > 1.0 +/- 0.33 > 1.0 +/- 0.0, respectively). There was a positive correlation between bcl-2 and p53 protein expression in normal skin (r = 0.966, p = 0.0001), non-tumorigenic (r = 0.775, p = 0.0001), pretumorigenic (r = 0.830, p = 0.001), and tumorigenic lesions (r = 0.757, p = 0.003).

CONCLUSIONS

Bcl-2 and p53 proteins are altered in the keratinocytic hyperproliferative lesions. Determination of whether these alterations reflect underlying gene mutations will require further investigations.

Chronic hyperplastic candidosis/candidiasis (candidal leukoplakia)

Chronic hyperplastic candidosis/candidiasis (CHC; syn. candidal leukoplakia) is a variant of oral candidosis that typically presents as a white patch on the commissures of the oral mucosa. The major etiologic agent of the disease is the oral fungal pathogen Candida predominantly belonging to Candida albicans, although other systemic co-factors, such as vitamin deficiency and generalized immune suppression, may play a contributory role. Clinically, the lesions are symptomless and regress after appropriate antifungal therapy and correction of underlying nutritional or other deficiencies. If the lesions are untreated, a minor proportion may demonstrate dysplasia and develop into carcinomas. This review outlines the demographic features, etiopathogenesis, immunological features, histopathology, and the role of Candida in the disease process. In the final part of the review, newer molecular biological aspects of the disease are considered together with the management protocols that are currently available, and directions for future research.

Oral lichen planus and malignant transformation: is a recall of patients justified?

There has been a continuous debate regarding the possible malignant potential of oral lichen planus (OLP). Based on the results from follow-up studies, OLP is regarded by several authors as a pre-malignant condition, and patients with OLP have been recommended to have their lesions monitored two to four times annually. This recommendation needs reconsideration, because a recall system of all patients with OLP requires substantial economic resources. In a reality where such resources are limited, a recall system must be weighed against other benefits and the fact that the malignant potential of OLP is most likely very low. The present review focuses on the diagnostic criteria for OLP, the pre-malignant potential of OLP, and the extent to which the available information can be used to reduce morbidity and mortality of oral cancer related to OLP.

Large-scale preparation of high-molecular weight DNA from buccal mucosa

Four non-invasive methods of sampling DNA from buccal mucosa, simple rinses, scrubbing with cotton balls, scrubbing with toothbrushes and rinses after scrubbing with toothbrushes, were investigated. Scrubbing with toothbrushes yielded 5.79 +/- 5.56 microg of DNA rich in high-molecules, while less than one eighth the amount was recovered by scrubbing with cotton balls. Rinses after scrubbing with toothbrushes gave 50.0 +/- 46.0 microg of DNA and simple rinses 34.4 +/- 35.7 microg, although the DNA was considerably degraded. DNA specimens obtained from buccal cells were shown to be more or less in the process of degradation including apoptosis. For minisatellite analysis, only DNA prepared by scrubbing with toothbrushes could be used, while all specimens could be applied to PCR analyses. Since scrubbing with toothbrushes is painless and harmless, we recommend this method. Subsequent rinsing will yield a large amount of DNA suitable for many PCR analyses.

Histopathological analysis of apoptosis, and expression of p53, bcl-2, bax, and Ki-67 in laryngeal squamous cell carcinomas and dysplasia

The growth of neoplasia is determined by the proliferation and loss of cells. The purpose of this study is to determine the frequency of apoptosis in laryngeal carcinomas and to examine its relationship to the pathological parameters, including ki-67 expression, and to expression of p53, bcl-2, and bax protein. The materials are 67 cases of laryngeal squamous cell carcinomas (SCCs) and 22 cases of squamous dysplasia using biopsy and surgery specimens. Apoptotic cells were determined by the modified TUNEL method. Expressions of p53, bcl-2, and bax, i.e. apoptosis-related genes, and ki-67, a proliferation marker, were immunohistochemically examined. The relationships between apoptosis and the clinicopathological findings were studied. The stage of the carcinoma was not related to the apoptotic index. The expression of p53 was frequently detectable in the advanced carcinomas with T3, T4 and N-positive. The apoptotic index was not significantly related to recurrence, metastasis or histological differentiation. Apoptosis occurred frequently in the cornified areas of well differentiated SCCs. The expressions of ki-67 observed in the poorly differentiated SCCs was significantly higher than that observed in the well differentiated SCCs (P< 0.01). The apoptotic index increased after irradiation in the carcinoma. No relationship was found between apoptotic index, ki-67 index, and expression of p53, bcl-2 and bax. The apoptotic index obtained form the SCCs was significantly higher than that obtained form squamous dysplasias (P < 0.05). Various apoptosis-related findings including p53 expression were observed in the advanced type of laryngeal SCCs, and apoptosis of the carcinoma was suggested to be controlled by complicated factors including bcl-2.

The epidemiology of lip cancer: a review of global incidence and aetiology

Lip cancer (140 ICD-9) is a form of oral cancer that has a distinctive global epidemiology. This review summarises global incidence rates for male and female lip cancer with the aid of cancer atlases. High male lip cancer rates are reported for regions of North America (12.7 per 100 000 per annum), Europe (12.0 per 100 000 per annum) and Oceania (13.5 per 100 000 per annum), while it is virtually unknown in parts of Asia. Factors commonly cited as important in the aetiology of lip cancer include solar radiation, tobacco smoking and viruses. An attempt is made to summarise the evidence for factors that may be important in lip carcinogenesis. While incidence rates are generally stable or falling among males worldwide, they are rising in many female populations. The aetiology of the disease is far from established and much information regarding its pathogenesis is based on anecdotal rather than case-controlled epidemiological evidence. The epidemiology of lip cancer supports the proposal that the lip should be considered as a distinct cancer site, rather than being included with other forms of intraoral cancer.