Corrado Minimo

Frequent Loss of pRb2/p130 in Human Ovarian Carcinoma

Purpose: RB2/p130, a member of the retinoblastoma gene family, maps to human chromosome 16q12.2, a region in which deletions have been found in several human neoplasms including breast, prostatic, and ovarian carcinoma. We sought to evaluate pRb2/p130 protein expression and function in ovarian carcinoma. Experimental Design: pRb2/p130 expression was detected by immunohistochemical and Western blot analyses in 45 primary ovarian carcinoma samples. Results: Immunohistochemical analysis revealed loss or decrease of pRb2/p130 expression in 18 cases (40%). pRb2/p130 expression was mostly nuclear and inversely correlated to the tumor grade (P < 0.05). Western blot analysis correlated with immunohistochemical expression. Reverse transcription-PCR followed by Southern blot analysis was performed on a representative set of 20 ovarian carcinomas. RB2/p130 mRNA levels were consistent with protein expression. We found a significant increase in the percentage of G1-phase-arrested cells in CAOV3 and A2780 ovarian carcinoma cell lines after transduction with an adenovirus carrying the RB2/p130 gene (Ad-CMV-RB2/p130). Conclusions: These data indicate that loss or decrease of pRb2/p130 expression is a frequent event in ovarian carcinoma and is regulated mostly at the transcriptional level. Moreover, pRb2/p130 overexpression is able to arrest cell growth in ovarian carcinoma cells, suggesting the putative role of pRb2/p130 as a tumor suppressor in this malignancy.

pRb2/p130, vascular endothelial growth factor, p27 (KIP1), and proliferating cell nuclear antigen expression in hepatocellular carcinoma: their clinical significance

Hepatocarcinoma (HCC) is the fifth most common cancer, with more than one million fatalities occurring annually worldwide. Multiple risk factors are associated with HCC disease etiology, the highest incidence being in patients with chronic hepatitis B virus and hepatitis C virus, although other factors such as genetic makeup and environmental exposure are involved. Multiple genetic alterations including the activation of oncogenes and inactivation of tumor suppressor genes are required for malignancy in human cancers and are correlated with increased stages of carcinogenesis and further tumor progression. In this study of 21 HCC patients, we analyzed pRb2/p130, vascular endothelial growth factor (VEGF), p27(KIP1), and proliferating cell nuclear antigen as potential HCC molecular biomarkers. In our sample set, we found that p27(KIP1) was absent. Univariate survival analysis showed that proliferating cell nuclear antigen expression (diffuse staining >50% of positive cells in tumor) was confirmed as a significant HCC prognostic biomarker for determining patient survival agreeing with previous studies (P = 0.0126, log-rank test). Lower pRb2/p130 expression was associated to a borderline P value of inverse correlation with tumor malignancy and to a positive correlation with respect to the time from HCC diagnosis (Spearman coefficient = 0.568; P < 0.05). Conversely, higher VEGF expression was associated with a poor survival (P = 0.0257, log-rank test). We demonstrate for the first time that pRb2/p130 is inversely correlated with VEGF expression and tumor aggressiveness (P < 0.05) in p27(KIP1)-negative HCC patients. pRb2/p130 and VEGF expression are independent from tumor staging, suggesting their possible role as independent prognostic molecular biomarkers in HCC. Furthermore, we have evidence that VEGF together with pRb2/p130 may act as new HCC biomarkers in a p27(KIP1)-independent manner. Additional studies with larger numbers of patient data would allow the use of multivariable techniques and would be able to further identify patients with poorer survival.

Immunohistochemical evaluation of pRb2/p130, VEGF, EZH2, p53, p16, p21waf-1, p27, and PCNA in Barrett's esophagus.

Control of the G1/S‐phase transition as well as angiogenic switch are two of the most studied mechanisms in cancer. The current study examined the correlation between the immunohistochemical expression of pRb2/p130, VEGF, EZH2, p53, p16, p21waf‐1, p27, and PCNA in Barretts esophagus (BE). Overall, p53 showed a much higher expression in BE patients (up to 50%) than in controls (1–10%) (P < 0.005). Also p21 showed a downregulation in BE when compared to normal esophagus (70% of cells vs. 65%), but the difference did not show any statistical significance (P = 0.45). pRb2/p130 was detected in 80% of cells in normal controls, but showed positive in only 20% of cells in BE biopsies. Additionally, Rb2/p130 expression was inversely correlated to that of VEGF, EZH2, and PCNA (P < 0.0001, P = 0.0032, P < 0.001, respectively). p27 stained more intensely and in a widespread manner (70%) cells in normal esophageal tissues but about only 30% in BE samples (P < 0.001). Lastly, in accordance with other reports, we also found p16 expressed by immunohistochemistry at high levels in normal controls and at low levels in BE (P < 0.001). In conclusion, p16, p21, p27, and p53 staining confirmed previously published data. Interestingly, pRb2/p130 expression was found significantly decreased in metaplastic epithelium compared to normal controls and showed significant inverse correlation with the expression of other markers, such as VEGF, EZH2, and PCNA. These data, taken together, indicate that these molecular events occurring in Barretts metaplasia (BM) may represent one of the many steps taking place during esophageal malignant progression such as impairment of cell‐cycle control, altered differentiation, and unbalanced angiogenesis. J. Cell. Physiol. 207: 512–519, 2006.

Expression of Cell Cycle–Regulated Proteins pRB2/p130, p107, E2F4, p27, and pCNA in Salivary Gland Tumors: Prognostic and Diagnostic Implications

The retinoblastoma family consists of the tumor suppressor nuclear phosphoprotein pRb/p105 and related proteins p107 and pRb2/p130. Recent immunohistochemical studies of the retinoblastoma family of proteins in lung and endometrial cancer and choroidal melanomas show a tight inverse correlation between the histologic grading in the most aggressive tumor types and pRb2/p130 expression. This led us to investigate the role of pRb2/p130 in salivary tumors. We studied the expression of pRb2/p130, p107, E2F4, p27, and PcNA by immunohistochemistry in a panel of 44 salivary gland tumors. We found a direct correlation between the cytoplasmic expression of pRb2/p130 and tumor grading and the presence of metastasis that was highly statistically significant (P < 0.001). Additionally, increased cytoplasmic pRb2/p130 expression was significantly correlated with a decreased probability of survival (P < 0.001). Interestingly, p107 nuclear expression showed a strong direct correlation when compared with the same variables. pRb2/p130 showed the highest percentage of undetectable nuclear levels in the specimens examined and the tightest inverse correlation (P < 0.0001) with both the histologic grading and pCNA expression in malignant salivary tumors. Additionally, E2F4 showed an identical localization pattern as to that of pRb2/p130. These data suggests an important role for pRb2/p130 in the pathogenesis and progression of certain salivary gland cancers.

The Role of pRb2/p130 Protein in Diagnosing Lung Carcinoma on Fine Needle Aspiration Biopsies

The retinoblastoma gene family is composed of three members: the retinoblastoma gene, one of the most studied tumor suppressor genes, and two related genes: p107 and pRb2/p130. These proteins are also known as the pocket proteins due to a unique structural and functional domain composed of subdomains A and B separated by a spacer region that is highly conserved among each of the proteins. These proteins exhibit unique growth suppressive properties that are cell type specific, suggesting that although the pocket proteins may complement each other, they are not fully functionally redundant. With the development of antibodies recognizing these three proteins it is now possible to detect expression in formalin-embedded specimens. Recent studies on 235 lung cancers, using immunohistochemical techniques, suggested an independent role for Rb2/p130 in the development and/or progression of human lung carcinoma. We found a statistically significant inverse relationship between the histological grading (degree of malignant potential) and the expression of pRb/p105, p107 and pRb2/p130 in squamous cell carcinomas, meaning that an increase in grading resulted in a significant decrease in protein expression. This phenomenon was particularly evident for pRb2/p130 (p < .0001) which had the highest percentage of undetectable levels in all the specimens examined and the tightest inverse correlation (p value) with both the histological grading and PCNA expression in the most aggressive tumor types, suggesting an important role for pRb2/p130 in the pathogenesis and progression of certain lung cancers. We further explored the expression of pRb2/p130 protein in routine archival FNAB cytological material from 30 Patients with lung cancer using immunocytochemical techniques, comparing protein expression with tumor type. Two pathologists evaluated the staining pattern and scored the percentage of positive cells. Of the 30 neoplasms, 27 displayed a positive staining for pRb2/p130. In particular, we detected pRb2/p130 in 9 (100%) squamous carcinomas, 11 (84%) adenocarcinomas, 5 (100%) BAC, and 2 (66%) SCC. The percentage of positive nuclei varied in different tumors with the highest expression level in adenocarcinomas. Immunocytochemistry represents a sensitive method for detection of pRb2/p130 expression in cytological or archival specimens, and the level of detection seems to be comparable to paraffin sections. Therefore, this methodology could be used in the preoperative evaluation of routine cytological specimens in order to improve the diagnostic and prognostic evaluation of lung cancer patients.

Anti-cytokeratin 20 Staining of Merkel Cells Helps Differentiate Basaloid Proliferations Overlying Dermatofibromas from Basal Cell Carcinoma

Background:  Basaloid epidermal proliferations (BEP), morphologically resembling basal cell carcinoma (BCC), have been described overlying dermatofibromas. Distinguishing the two is important because of non‐aggressiveness of BEP and local aggressiveness of BCC. The aim of this study is to determine whether CK20 antibody staining for Merkel cells can be used as an adjunct method to differentiate BEP from BCC.

Relevance of immunocytochemistry on thin-layer cytology in thyroid lesions suspicious for medullary carcinoma. A case-control study.

BackgroundFine needle aspiration cytology represents the most important tool in the diagnosis of thyroid nodules, mostly in discriminating malignant from benign lesions. The diagnosis of medullary thyroid carcinoma (MTC) may present some problems related to its deceptive morphologic picture. This diagnosis may be supported by immunocytochemistry (ICC), which may be difficult to carry out on the conventional smears. DesignThe diagnostic efficacy of ICC for the diagnosis of MTC with respect to other thyroid neoplasms on slides processed by thin-layer cytology (TLC) is evaluated. PatientsIn the period between January 2002 and December 2005, 8,200 FNAB were processed. ICC on TLC slides was required in 33 cases. Conventional smears were fixed in ethanol, whereas TLC slides were processed with the Thin Prep 2000 method. All slides were then stained with Papanicolaou. In all cases where MTC was morphologically suspected, ICC for calcitonin, monoclonal carcinoembryonic antigen, and thyroglobulin was carried out only on TLC slides. ResultsThirty-three thyroid cytologic cases had ICC on the TLC slides, including 22 follicular proliferations and 11 malignant lesions. The application of ICC on TLC was conclusive in 32 cases and inconclusive in 1 case. Twenty cases underwent surgery. No false-positive and false-negative cases were found. Sensitivity and specificity were 100%, and the overall diagnostic accuracy was 100%. ConclusionsICC can be successfully applied on TLC slides. The combined results of morphology and a small immunopanel including thyroglobulin, calcitonin, and carcinoembryonic antigen yields a 100% diagnostic efficacy for MTC. Condensed AbstractFine needle aspiration cytology is an excellent technique for diagnosing malignant neoplasms of the thyroid, especially those derived from the follicular cells. A correct preoperative diagnosis of C-cell–derived tumors (MTC), which is essential for both the surgical approach to the primary tumor and the management of the patient, should rely not only on the morphologic picture but also on the immunocytochemical yielding using an immunopanel, which is particularly satisfactory on the TLC slides.

Grading of upper urinary tract transitional cell carcinoma by computed DNA content and p53 expression

OBJECTIVES Transitional cell carcinomas of upper urinary tract (uttTCC) constitute 5% to 6% of all urothelial tumors. Ureteropyeloscopy has become the standard for clinical evaluation of uutTCC. Moreover, endoscopic treatments have been advocated as a conservative approach for low grade tumors or patients with intermediate grade tumors whose renal function is compromised. Therefore, grading has become the most predictive variable in defining therapeutic approach. In addition to morphologic evaluation, a series of biologic markers may be used to increase the accuracy of grading such as DNA analysis and p53 protein expression. In this study, we have evaluated these markers by means of cell image analysis with the SAMBA 400 system. METHODS Thirteen cases of uttTCC were studied with cytologic smear, cell block, and histologic confirmation. DNA analysis was performed on cytologic smear. Immunostaining was performed on cell blocks. A grade was assigned on the basis of DNA evaluation and p53 expression quantitation. These grades were combined for each case and compared with the initial cytologic grading and the final histologic grading. RESULTS Cytology alone diagnosed TCC in all but 1 case that was diagnosed atypical. Discrepancies were found in primary grading: cytologic grading concurred with histologic grading in 6 of the 13 cases. CONCLUSIONS These results, although in a limited but selected number of cases, show the potential of computerized evaluation of biologic markers as parameters for a more objective grading of tumors.

Chondrosarcoma of the Jaw: A Closer Look at its Management

c hondrosarcoma is a malignant cartilaginous tumor arely involving the mandible. The prognosis is genrally poor depending on the degree of differentiation nd the quality of the resection. This article details the various methods of treatent and provides some clarifications on the clinical spects as well as the therapeutic approach. Chondrosarcoma is classified by the World Health rganization (WHO) as a malignant tumor with ure hyaline cartilage differentiation characterized y the formation of cartilage, but not of bone, by umor cells. Chondrosarcoma accounts for approximately 10% o 20% of all primary malignant bone tumors and, xcluding multiple myeloma, represents the second ost common primary bone malignancy after osteoarcoma.