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

P21 Immunoexpression in Actinic Keratosis and Cutaneous Carcinomas

Actinic keratosis is a precancerous lesion of the skin with variable rates of transformation into non-melanocytic carcinomas. The present study aims to analyze p21 expression in actinic keratosis and cutaneous squamous carcinomas. P21 expression analysis revealed a positive reaction in 63 (71.4%) of the investigated cases. The immunostaining analysis revealed positivity in 82.1% of the studied actinic keratosis cases and in 43.9% of the investigated carcinomas. High scores of immunoreactions were identified only for the well-differentiated and for the carcinomas in initial stages. Association of p21 expression with pre-invasive or well-differentiated invasive lesions in early stages of tumor progression suggests that p21 may be an early event in squamous carcinogenesis.

Correlation between cell cycle proteins and hMSH2 in actinic cheilitis and lip cancer

This study aims to evaluate and verify the relationship between the immunoexpression of hMSH2, p53 and p21 in actinic cheilitis (AC) and lower lip squamous cell carcinoma (SCC) cases. Forty AC and 40 SCC cases were submitted to immunoperoxidase method and quantitatively analyzed. Expression was compared by Mann-Whitney test, Student t test or one-way ANOVA. To correlate the variables, Pearson's correlation coefficient was calculated. The expression of p53 and p21 showed no significant differences between histopathological grades of AC or lower lip SCC (p > 0.05). Immunoexpression of p53 was higher in SCC than in AC (p < 0.001), while p21 expression was more observed in AC when compared to SCC group (p = 0.006). The AC group revealed an inverse correlation between p53 and hMSH2 expression (r = -0.30, p = 0.006). Alterations in p53 and p21 expression suggest that these proteins are involved in lower lip carcinogenesis. Moreover, p53 and hMSH2 seem to be interrelated in early events of this process.

Expression of MAGE-A1-A12 subgroups in the invasive tumor front and tumor center in oral squamous cell carcinoma

MAGE-A proteins are highly expressed in oral squamous cell carcinoma (OSCC) and are promising targets for cancer immunotherapy. This study examined the presence of MAGE-A expression within the tumor center (TC) and tumor invasive front (TIF) and evaluated its relationship to poor prognosis. The expression rate of each MAGE-A subtype, A1-A12, was examined in 68 OSCCs at the TIF and TC. Slides (1-µm) of tissue microarrays (diameter =0.6 mm) were immunohistochemically stained, and the findings were correlated to clinical data. Approximately 95% of the tumors had MAGE-A expression. Higher expression in the TC was shown significantly for MAGE-A1, -A5, -A6, -A9 and -A12 (P<0.05). MAGE-A2 and -A3 exhibited the opposite behavior (not significant, P>0.05). Age, tumor size, grade and survival time were not associated with the expression of certain MAGE-A subgroups. When expression in the whole tumor tissue was considered, only MAGE-A1 was expressed at a significantly higher rate in male patients (P=0.034). At the TIF, MAGE-A9 and the UICC disease stage were significantly correlated (P=0.0263), and MAGE-A6 and the UICC disease stage exhibited a strong trend (P=0.0596). The expression of MAGE-A3, -A4, -A5, -A9 and -A11 was significantly associated with lymph node metastasis, while MAGE-A4 was expressed in all regions of the tumors (TIF and TC). This study showed that higher expression of most MAGE-A antigens occurred at the TC rather than at the TIF. MAGE‑A1, -A3, -A4, -A5, -A9 and -A11 were significantly associated with clinically advanced stages of disease and seem to be of particular interest.

Molecular changes in invasive front of oral cancer

Treatment planning for oral squamous cell carcinoma (OSCC) is based on the clinical TNM (Tumor, Node and Metastasis) classification. This system operates on the assumption that small tumours without clinical spread have a better prognosis than larger tumours with metastases. However, it is a well-known fact that some tumours with the same clinical staging show different growth patterns and clinical behaviour. This makes the prognosis for patients with OSCC difficult to predict on the basis of clinical staging alone. Although many histopathological characteristics of OSCC have been identified as prognostic factors, none is believed to be completely infallible. Therefore, a great need exists for more reliable prognostic markers, which will assist in treatment decisions. It is now well documented that several molecular events of significance for tumour spread, such as gain and loss of adhesion molecules, secretion of proteolytic enzymes, increased cell proliferation and initiation of angiogenesis occur at the tumour–host interface or invasive front, where the deepest and presumably most aggressive cells reside. This review describes the various molecular events and interactions, which take place in the invasive front of the OSCC, and elucidates their role as prognostic markers.

The role of p21Waf1/CIP1 as a Cip/Kip type cell-cycle regulator in oral squamous cell carcinoma (Review)

Oral Squamous Cell Carcinoma (OSCC) is biologically characterized by the accumulation of multiple genetic and molecular alterations that end up clinically characterized as a malignant neoplasm through a phenomenon known as multistep. The members of the Cip/Kip family, specifically p21Waf1/CIP1, are responsible for cell cycle control, blocking the transition from phase G1 to phase S. We made a search of articles of peer-reviewed Journals in PubMed/ Medline, crossing the keywords. The goal of this paper is to determine the relationship between p21Waf1/CIP1 expression and several clinical and pathological aspects of OSCC, their relationship with p53 and HPV, as well as genetic alterations in their expression pattern, their use as a prognosis market in the evolution of precancerous lesions and their roles in anticancer treatments. The results of p21WAF1/CIP1 expression in OSCC showed mixed results in terms of positivity/negativity throughout different studies. It seems that, although p21Waf1/CIP1 expression is controlled in a p53-dependent manner, coexpression of both in OSCC is not intrinsically related. Although the presence of HPV viral oncoproteins increases p21Waf1/CIP1 levels, the small number of studies, have forced us to disregard the hypothesis that HPV infected lesions that present better prognosis are due to a p21Waf1/CIP1-dependent control. The role of p21WAF1/CIP1 as cell-cycle regulator has been well described; however, its relationship to OSCC, the clinical and pathological variables of tumors, HPV and different treatments are not entirely clear. Thus, it would be very interesting to pursue further study of this protein, which may have a significant value for the diagnosis, prognosis and therapy of this type of tumors.

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.

Immunohistochemical analysis of p53, APE1, hMSH2 and ERCC1 proteins in actinic cheilitis and lip squamous cell carcinoma

AIMS

This study has compared the tissue expression of the p53 tumour suppressor protein and DNA repair proteins APE1, hMSH2 and ERCC1 in normal, dysplastic and malignant lip epithelium.

METHODS AND RESULTS

Morphological analysis and immunohistochemistry were performed on archived specimens of normal lip mucosa (n=15), actinic cheilitis (AC) (n=30), and lip squamous cell carcinoma (LSCC) (n=27). AC samples were classified morphologically according to the severity of epithelial dysplasia and risk of malignant transformation. LSCC samples were morphologically staged according to WHO and invasive front grading (IFG) criteria. Differences between groups and morphological stages were determined by bivariate statistical analysis. Progressive increases in the percentage of epithelial cells expressing p53 and APE1 were associated with increases in morphological malignancy from normal lip mucosa to LSCC. There was also a significant reduction in epithelial cells expressing hMSH2 and ERCC1 proteins in the AC and LSCC groups. A higher percentage of malignant cells expressing APE1 was found in samples with an aggressive morphological IFG grade.

CONCLUSIONS

Our data showed that epithelial cells from premalignant to malignant lip disease exhibited changes in the expression of p53, APE1, hMSH2 and ERCC1 proteins; these molecular change might contribute to lip carcinogenesis.

Immunoexpression of bone morphogenetic protein-2 (BMP-2), BMP receptor type IA, and BMP receptor type II in metastatic and non-metastatic lower lip squamous cell carcinoma

BACKGROUND

The aim of this study was to evaluate the expression of bone morphogenetic protein-2 (BMP-2), BMPR-IA, and BMPR-II in metastatic and non-metastatic lower lip squamous cell carcinoma (LLSCC).

METHODS

Twenty LLSCC with regional nodal metastasis and 20 LLSCC without metastasis were selected for analysis of the immunoexpression of BMP-2, BMPR-IA, and BMPR-II. The percentage of positive cells was evaluated according to the following parameters: score 1 (staining in 0-50% of cells), score 2 (staining in 51-75% of cells), and score 3 (staining in >75% of cells). Immunostaining intensity was evaluated according to the following scores: score 1 (absent or weak expression) and score 2 (strong expression).

RESULTS

Regarding the percentage of positive cells, most tumors with and without metastasis showed score 3 for both BMP-2 (P = 0.655) and BMPR-IA (P = 0.655). For BMPR-II, metastatic tumors exhibited higher percentage of positive cells in comparison with non-metastatic tumors (P = 0.049). With respect to immunostaining intensity, most LLSCCs with and without metastasis showed score 2 for BMP-2 (P = 1.000) and score 1 for BMPR-II (P = 1.000). For BMPR-IA, most metastatic tumors presented score 2, whereas most non-metastatic tumors showed score 1 (P < 0.001). Strong expression of BMPR-IA showed a statistically significant association with advanced clinical staging (P < 0.001) and high score of malignancy (P = 0.028).

CONCLUSIONS

The results of this study suggest that disturbances in the BMP-2 signaling pathway may be involved in the development of LLSCC and that the strong expression of BMPR-IA might be indicative of the development of metastasis in these lesions.

Altered β-catenin expression related to cancer progression on actinic cheilitis and squamous cell carcinoma of the lip

β-Catenin is a bifunctional protein related to cell adhesion and gene transcription when activated by Wnt pathway. Altered expression of β-catenin was related to loss of differentiation, more aggressive phenotype, increase of tumor invasion, and poor prognosis in a number of different cancers. Actinic cheilitis is caused by excessive exposure to ultraviolet radiation and has a high potential to suffer malignant transformation into squamous cell carcinoma (SCC) of the lip, the most frequent oral malignancy. Studies of oral cancer have shown the correlation of β-catenin expression and oral SCC prognosis, and loss of membrane expression may be considered as a potential marker for early tumor recurrence. Thirty-five cases of actinic cheilitis and 12 cases of SCC of the lip were select and submitted to immunohistochemical staining using β-catenin antibody. β-Catenin was positive on the membrane for all cases. Eighty-five percent of actinic cheilitis cases showed cytoplasmatic staining, and 22% nuclear staining. Eighty-three percent of SCC was positive for β-catenin, and none of them had nuclear staining. Cytoplasmatic and nuclear staining of β-catenin on studied cases point to pathway alterations. Results demonstrated that β-catenin expression is altered on epithelial dysplasia, and it is related to degree of alterations.

Comparative evaluation of antiproliferative, antiangiogenic and apoptosis inducing potential of black tea polyphenols in the hamster buccal pouch carcinogenesis model

BACKGROUND

To evaluate the relative chemopreventive efficacy of two black tea polyphenols, Polyphenon-B [P-B] and BTF-35 on 7,12-dimethylbenz [a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.

METHODS

Hamsters were divided into 6 groups. The right buccal pouches of animals in groups 1-3 were painted with 0.5% of DMBA three times a week for 14 weeks. While hamsters in group 1 received no further treatment, animals in groups 2 and 3 received diet containing 0.05% P-B and BTF-35 respectively, four weeks before DMBA painting that was continued until the end of the experiments. Animals in groups 4 and 5 were given P-B and BTF-35 alone respectively as in groups 2 and 3. Group 6 animals served as the untreated control. All the animals were sacrificed after 18 weeks. The expression of p21, cyclin D1, glutathione S-transferase pi (GST-P), nuclear factor kappa B (NF-kappaB), Bcl-2, Bax, cytochrome C, caspase-3, caspase-9, poly(ADP-ribose) polymerase (PARP), cytokeratins and vascular endothelial growth factor (VEGF) was analysed by RT-PCR, immunohistochemical and Western blot analyses.

RESULTS

DMBA treated animals developed buccal pouch carcinomas that displayed increased expression of p21, cyclin D1, GST-P, NF-kappaB, cytokeratins, VEGF and Bcl-2 with decreased expression of Bax, cytochrome C, caspase-3, caspase-9, and PARP. Dietary administration of both P-B and BTF-35 reduced the incidence of DMBA-induced HBP carcinomas by modulating markers of cell proliferation, cell survival, tumour infiltration, angiogenesis, and apoptosis.

CONCLUSION

The results of the present study provide a mechanistic basis for the chemopreventive potential of black tea polyphenols. The greater efficacy of BTF-35 in inhibiting HBP carcinogenesis and modulating multiple molecular targets may have a potential role in the prevention of oral cancer.

Expressão do p53 no carcinoma epidermóide do lábio

OBJETIVO: Verificar o valor da expressão do p53 no carcinoma epidermóide (CEC) de lábio. MÉTODO: O estudo imunohistoquímico foi feito em material fixo em formol e mantido em bloco de parafina, corado com anticorpos anti-p53, segundo técnica da Streptavidina-Biotina-Peroxidase. Para análise estatística, foi empregado o teste de Fisher para a diferenciação de grupos em relação às variáveis do estudo. RESULTADOS: A expressão do p53 foi positiva em 87,5% do CEC bem diferenciado, 60% no moderadamente diferenciado e 91,67% no pouco diferenciado. Nas margens de ressecção cirúrgica foi negativa em 94,23% e positiva em 5,77%, havendo associação entre o grau de diferenciação e a expressão do p53 (p=0,05). CONCLUSÃO: A expressão do p53 foi positiva na lesão primária e negativa na margem de ressecção cirúrgica, mas não é determinante de mudanças no paradigma cirúrgico.