Ki67 Expression (ki67 + expression)

Distribution by Scientific Domains

Selected Abstracts

Altered patterns of the interferon-inducible gene IFI16 expression in head and neck squamous cell carcinoma: immunohistochemical study including correlation with retinoblastoma protein, human papillomavirus infection and proliferation index

B Azzimonti
Aims:, To investigate whether the expression of interferon (IFN)-inducible gene IFI16 is inversely related to proliferative activity in vivo, we compared immunohistochemical reactivity of IFI16 in a series of head and neck squamous cell carcinomas (HNSCCs) with their proliferation index and the cell cycle regulator pRb. As human papillomavirus (HPV) infection is manifested by changes in the function or expression level of host genes such as IFN-inducible genes, we also investigated the presence of HPV DNA to determine whether head and neck cancers associated with HPV DNA can be distinguished from tumours that are presumably transformed by other mechanisms. Methods:, Thirty-six HNSCCs were evaluated for IFI16, pRb and Ki67 expression by immunohistochemistry. The presence of HPV was also detected by polymerase chain reaction. Nine tumours were located in the oropharynx (tonsillar area) and 27 in the larynx. Results:, HPV DNA was found in 14 of 25 (56%) laryngeal SCCs and in five of nine (56%) tonsillar SCC specimens examined; 17 out of the 19 HPV-DNA-positive cases showed high-grade IFI16 expression. Overall, proliferative activity was significantly related to tumour differentiation and histological grading. IFI16 protein expression was significantly inversely correlated with Ki67 (P = 0.039). Low-proliferating tumours positive for IFI16 staining showed a marked expression of pRb and a better prognosis than those whose tumours had low IFI16, pRb levels and a high proliferation index. Conclusions:, To our knowledge, this is the first expression analysis of the IFN-inducible IFI16 gene in HNSCC. Low-proliferating tumours positive for IFI16 staining showed a marked expression of pRb and a better prognosis than those whose tumours had low IFI16, pRb levels and a high proliferation index. [source]

Odontogenic keratocyst expresses vascular endothelial growth factor: an immunohistochemical study

G. K. Mitrou
Background:, Vascular endothelial growth factor (VEGF) expression may act as a sensitive measure of the angiogenic potential of a lesion. Furthermore, VEGF has been implicated in the pathogenesis of cystic tumors and inflammatory odontogenic cysts. Thus, we studied the expression of VEGF in the epithelium of odontogenic keratocyst (OK) in association with cell proliferation and apoptosis. Methods:, Forty-two cases of OK, 26 cases of dentigerous cyst (DC), and 15 cases of residual cyst (RC) were retrospectively examined by immunohistochemistry for VEGF, Ki67/Mib-1 and anti-caspase-3. For VEGF and caspase-3, the intensity of immunostaining was qualitatively assessed, while for the evaluation of Ki67 the average number of positively stained nuclei in 10 high-power microscopic fields (400) was calculated. Results:, The VEGF expression was stronger in OK when compared with DC (P < 0.007). The rate of nuclear Ki67 expression in OK was significantly higher than that in DC (P < 0.001) and RC (P < 0.001). Cytoplasmic caspase-3 expression was statistically more intense in RC than in OK (P = 0.001) or DC (P < 0.001). A statistically significant correlation was seen in OK for Ki67 (P < 0.001) and VEGF (P = 0.023), but not for caspase-3. Multiple regression analysis revealed a linear relationship between VEGF and Ki67. Conclusions:, The VEGF was expressed in the epithelium of OK, DC, and RC with a variable intensity, and in OK VEGF expression was related to Ki67. It is suggested that VEGF expression by the odontogenic epithelium is not induced solely by inflammation. [source]

Diversity of human papillomavirus types in periungual squamous cell carcinoma

A. Kreuter
Summary Background, There is accumulating evidence that infections with certain high-risk ,-human papillomaviruses (HPVs) are involved in the pathogenesis of digital squamous cell carcinomas (SCCs) and their precursor lesions (SCCs in situ). Objectives, This study was initiated to search for ,- and ,-HPV infections in a collective of SCC and SCC in situ located on the hands. Methods, HPV typing for 36 high-risk and low-risk ,-HPV types and 25 ,-HPV types was performed in SCCs located at different sites of the hands. Additionally, immunohistochemical staining for p16INK4a and Ki67 was performed in 15 samples. Results, In total, 25 SCCs/SCCs in situ (six periungual lesions, eight lesions from the proximal or lateral part of the finger, and 11 lesions from the dorsal part of the hand) were analysed for the presence of ,- and ,-HPV types. Only one lesion (an SCC in situ positive for HPV11 and HPV31) of the dorsal hand and none of the proximal or lateral part finger lesions were ,-HPV positive. In contrast, all six periungual lesions were ,-HPV positive, and the majority (83%) of them carried HPV types other than HPV16 (HPV26, HPV33, HPV51, HPV56 and HPV73). ,-HPV types were found in only two biopsies. p16INK4a and Ki67 expression was significantly higher in HPV-positive lesions as compared with HPV-negative tumours, and both markers significantly correlated with each other. Conclusions, In contrast to other locations of the hands, periungual SCCs are frequently associated with ,-HPV infections. Several high-risk HPV types other than HPV16 can induce periungual SCCs. Given the high recurrence rate and high proliferative activity of HPV-associated periungual SCCs, aggressive treatment and close follow-up of these tumours is mandatory. [source]

Human papillomavirus-associated increase in p16INK4A expression in penile lichen sclerosus and squamous cell carcinoma

D.M. Prowse
Summary Background, Human papillomaviruses (HPVs) are sexually transmitted human carcinogens that may play a role in the oncogenesis of penile cancer. Objectives, To investigate the role of HPV infection and expression of the tumour suppressor protein p16INK4A in the pathogenesis of penile cancer. Methods, By means of polymerase chain reaction amplification and reverse hybridization line probe assay to detect HPV infection, and immunohistochemical staining for p16INK4A and Ki67, we analysed 26 penile squamous cell carcinomas (SCCs) and 20 independent penile lichen sclerosus (LS) lesions from 46 patients. Results, HPV DNA was found in 54% of penile SCCs and 33% of penile LS cases in single and multiple infections. High-risk HPV 16 was the predominant HPV type detected. No relationship between Ki67 expression and HPV infection was observed. Strong immunostaining for p16INK4A correlated with HPV 16/18 infection in both penile LS and penile SCC. In our penile SCC series the cancer margins were also associated with penile LS in 13 of 26 lesions, and HPV was detected in seven of the 13 SCC cases associated with LS and in six of the 11 SCC lesions not involving LS. Conclusions, Our study shows a high prevalence of HPV 16 and p16INK4A expression in penile lesions, consistent with an active role for HPV in interfering with the retinoblastoma pathway. High-risk HPV infection could be involved in the tumorigenic process in 50% of penile cancers, and the use of prophylactic HPV vaccines has the potential to prevent these cancers. [source]

Aggressive digital papillary adenocarcinoma: a review

H.-C. Hsu
Summary Vigorous treatment of aggressive digital papillary adenocarcinoma (ADPA), including amputation, has been recommended by most authors, but the appropriateness and effectiveness of excision as an alternative to amputation has not been systematically evaluated. To evaluate the appropriateness and effectiveness of excision as an alternative to amputation in the treatment of ADPA, we reviewed the clinical presentations, treatments and patient outcomes presented in case reports on ADPA available on Ovid MEDLINE. We also assessed the results of immunohistochemical staining for proliferation markers in one patient in order to explain the nonaggressive nature of ADPA noted in that patient. Except for the duration of lesions, there was no significant difference in clinical outcome between the excision and amputation groups. We also found that p63 may be a useful marker for distinguishing primary ADPA from metastatic adenocarcinomas. In addition, the intensity of Ki67 expression in tumour cells may be a marker of aggressive behaviour and thus be helpful in therapeutic decision-making. Wide excision with or without sentinel lymph-node biopsy is a feasible alternative to amputation. It should be considered in patients who present with a long-standing history of ADPA without evidence of underlying bone invasion or distant metastasis and with low-intensity expression of proliferation markers. [source]