Athanassios Dellas

p53 protein expression but not mdm-2 protein expression is associated with rapid tumor cell proliferation and prognosis in renal cell carcinoma

The clinical course of renal cell carcinoma (RCC) is highly variable. Overexpression of the p53 protein has been suggested as a possible prognostic parameter in RCC. Overexpression of the mdm-2 oncogene product has been shown to interact with the p53 function. To investigate the immunohistochemical overexpression of mdm-2 protein in comparison with that of p53 protein in RCC, 50 nonpapillary pT3 RCCs were immunostained for p53 protein (DO-7) and mdm-2 (1172). Tumor growth fraction (Ki-67 labeling index; MIB-1) was determined by immunohistochemistry. p53 positivity was detected in 16% of tumors. mdm-2 overexpression was seen in 30% of RCCs. There was a significant association between p53 and mdm-2 immunostaining (P=0.0006), suggesting that mdm-2 protein may contribute to p53 protein stabilization in RCC. p53 overexpression was associated with a high Ki-67 LI (P=0.0002), suggesting that p53 overexpression is involved in growth control in RCC. Survival analysis showed that Ki-67 LI (P=0.04) and p53 overexpression were associated with poor prognosis (P=0.0021), whereas mdm-2 overexpression was not related to patient outcome (P=0.73). A Cox regression analysis revealed tumor stage (P<0.001) and p53 overexpression (P<0.05) to be independent prognostic parameters. It is concluded that p53 but not mdm-2 may be of practical relevance in predicting patient prognosis in RCC.

Altered expression of mdm-2 and its association with p53 protein status, tumor-cell-proliferation rate and prognosis in cervical neoplasia

Recent results suggest that p53 inactivation is required for cervical‐carcinoma development. The mdm‐2 oncogene, which forms an auto‐regulatory feedback loop with the normal p53 protein, has been found amplified in human carcinomas, thus abolishing the anti‐proliferative function of p53. To investigate whether the mdm‐2/p53 interaction plays a role in cervical neoplasms, we performed an immunohistochemical study in archival fixed, embedded specimens that included 178 pre‐cancerous lesions (CIN) and invasive squamous‐cell carcinomas of clinical stage IB. In addition to p53, we assessed the p53‐associated protein, mdm‐2, and the Ki‐67 labelling index (LI). The presence of HPV was assessed by in situ DNA hybridization. Tumor expression of all nuclear proteins was scored as fraction of positive CIN or cancer nuclei. The analysis demonstrated a significant association of the Ki‐67 LI with grade of atypia in cervical neoplasms. p53 accumulation and mdm‐2 expression are higher in invasive carcinomas than in pre‐cancerous lesions. No correlation was observed with HPV status. An inverse correlation was found between increased tumor‐cell proliferation and mdm‐2 expression in invasive carcinomas (p < 0.0001). mdm‐2 expression was significantly associated with p53 accumulation (p < 0.02). However, the investigated nuclear proteins were not associated with overall survival in patients with invasive carcinomas. Cox stepwise‐regression analysis revealed regional lymph node status and depth of invasion to be independent parameters. Int. J. Cancer 74:421–425, 1997.

p53 suppresses type II endometrial carcinomas in mice and governs endometrial tumour aggressiveness in humans

Type II endometrial carcinomas are a highly aggressive group of tumour subtypes that are frequently associated with inactivation of the TP53 tumour suppressor gene. We show that mice with endometrium‐specific deletion of Trp53 initially exhibited histological changes that are identical to known precursor lesions of type II endometrial carcinomas in humans and later developed carcinomas representing all type II subtypes. The mTORC1 signalling pathway was frequently activated in these precursor lesions and tumours, suggesting a genetic cooperation between this pathway and Trp53 deficiency in tumour initiation. Consistent with this idea, analyses of 521 human endometrial carcinomas identified frequent mTORC1 pathway activation in type I as well as type II endometrial carcinoma subtypes. mTORC1 pathway activation and p53 expression or mutation status each independently predicted poor patient survival. We suggest that molecular alterations in p53 and the mTORC1 pathway play different roles in the initiation of the different endometrial cancer subtypes, but that combined p53 inactivation and mTORC1 pathway activation are unifying pathogenic features among histologically diverse subtypes of late stage aggressive endometrial tumours.

Combined PTEN and p27kip1 Protein Expression Patterns Are Associated with Obesity and Prognosis in Endometrial Carcinomas

Purpose: Phosphatase and tensin homologue deleted from chromosome 10 (PTEN) and p27kip1 proteins are key players of the Akt pathway, which is nutritionally regulated by insulin receptor signaling and influenced by estrogens. In this study, the prognostic relevance of the PTEN/p27kip1 protein expression in endometrial carcinoma in relationship to the body mass index (BMI) was determined. Experimental Design: BMI and prognosis of 452 surgically treated patients with endometrial carcinoma were correlated with histologic subtype, International Federation of Gynecology and Obstetrics (FIGO) stage, and differentiation grade. The expression of PTEN and p27kip1 was examined in 257 tumors by immunohistochemistry using a tissue microarray approach. Results: Lack of PTEN was observed in 136 of 257 (53%) tumors and absence of p27kip1 expression was observed in 106 of 225 (47%) tumors. Absence of both proteins was significantly associated with well-differentiated tumors [PTEN (P < 0.02) and p27kip1 (P < 0.009)]. Differentiation grade, tumor stage, and histologic type were independent of an increased BMI. Importantly, tumors of obese women expressed significantly less PTEN (P < 0.008) and less p27kip1 (P < 0.01) than tumors from nonobese patients. Combined absence of both PTEN and p27kip1 expression characterized a group of 75 (32%) tumors with favorable clinical outcome, particularly in the FIGO stages I and II (P = 0.003) of obese patients. Cox regression analysis revealed that PTEN/p27kip1 phenotype, FIGO stage, and histologic grade were independent predictors of prognosis in endometrioid endometrial carcinoma. Conclusions: Inactivation of PTEN/p27kip1 proteins is a specific feature in the progression of endometrial carcinoma in obese patients. The phenotype of the combined loss of PTEN/p27kip1 protein expression in obese patients is associated with a significantly better prognosis in endometrioid endometrial carcinoma.

Investigation of the Bcl-2 and C-myc expression in relationship to the Ki-67 labelling index in cervical intraepithelial neoplasia.

This is the investigation of the relationship between the neoplastic cell proliferation and the expression of bcl-2 and c-myc in human papillomavirus (HPV)-negative and HPV-positive cervical intraepithelial neoplasms (CIN). The expression of bcl-2 and c-myc was studied using quantitative immunohistochemistry in 20 specimens of normal cervical squamous epithelium and 73 specimens of CIN. To analyze the neoplastic cell proliferation rate, the Ki-67 labelling index was determined; the latter was significantly different between normal epithelium and various grades of CIN (p < 0.0001). The highest proliferation rate was found in high-grade CIN. In precancerous lesions, we found the number of bcl-2 positive cells lower than in normal epithelium, but with a significant difference between low-grade and high-grade CIN (p < 0.0001). The highest percentage of bcl-2 positive neoplastic cells was found in high-grade CIN. C-myc was rarely expressed in normal epithelium. Similar to the Ki-67 labelling index, c-myc immunostaining correlated with the histological grade of CIN, with the highest percentage of c-myc positive nuclei occurring in high-grade CIN (p < 0.0001). In contrast to bcl-2 immunoreactivity, the c-myc significantly was more expressed in high-risk HPV-positive than in HPV-negative lesions. The c-myc expression in CIN is closely related to the neoplastic cell proliferation rate. With progression of intraepithelial neoplasia, bcl-2 production in neoplastic cells increases with high co-expression of c-myc.

ASSESSMENT OF EGFR AND TGF-ALPHA EXPRESSION IN RELATIONSHIP TO HPV STATUS AND KI-67 DISTRIBUTION IN CERVICAL INTRAEPITHELIAL NEOPLASMS

Expression of epidermal‐growth‐factor receptor (EGFR), transforming growth factor alpha (TGF‐α) and Ki‐67 proliferation antigen in cervical intra‐epithelial neoplasms were analyzed. To examine the interrelationship of TGF‐α, EGFR, Ki‐67 and HPV status in dysplasia and carcinoma in situ, formalin‐fixed tissue sections of 92 women were immunostained with monoclonal antibodies to EGFR, TGF‐α and Ki‐67. The presence of HPV was assessed by in situ DNA hybridization. The highest positive TGF‐α expression was seen in the group of mild dysplasia. The difference was significant between the relatively high expression in mild dysplasia and the low occurrence in severe dysplasia and carcinoma in situ as well. The same relation could be found between TGF‐α expression in papilloma‐virus‐negative dysplasia and those with the presence of HPV 16/18. In contrast to these findings, the Ki‐67 proliferation marker was intensely detectable in severe dysplasia and carcinoma in situ. Ki‐67‐stained neoplastic cell nuclei were found in a significantly higher percentage of HPV‐positive than in HPV‐negative lesions. TGF‐α over‐expression is obviously combined with low proliferating activity and vice versa. Irrespective of the grade of dysplasia or HPV status, EGFR was expressed abnormally as compared with normal squamous epithelium. Over‐expression of TGF‐α in mild dysplasia could be associated with the autocrine pathway of cell‐growth regulation. In the presence of HPV 16/18 the EGFR/TGF‐α pathway for growth stimulation is probably not involved.

KPNA2 is overexpressed in human and mouse endometrial cancers and promotes cellular proliferation

Endometrial cancer is the most frequently occurring malignancy of the female genital tract in Western countries. Although in many cases surgically curable, about 30% of the tumours represent an aggressive and untreatable disease. In an attempt to establish a reliable prognostic marker for endometrial carcinomas disregarding their histological diversity, we investigated the expression of KPNA2, a mediator of nucleocytoplasmic transport, and other cell proliferation‐associated proteins and their correlation with cancer progression. We analysed patient tissue microarrays (TMAs) assembled from 527 endometrial cancer tissue specimens and uterus samples from a Trp53 knockout mouse model of endometrial cancer. Our data show that KPNA2 expression was significantly up‐regulated in human endometrial carcinomas and associated with higher tumour grade (p = 0.026), higher FIGO stage (p = 0.027), p53 overexpression (p < 0.001), activation of the PI3K/AKT pathway, and epithelial–mesenchymal transition. Increased nuclear KPNA2 immunoreactivity was identified as a novel predictor of overall survival, independent of well‐established prognostic factors in Cox regression analyses (hazard ratio 1.7, 95% CI 1.13–2.56, p = 0.01). No significant association between KPNA2 expression and endometrial cancer subtype was detected. In the mouse model, KPNA2 showed increased expression levels from precancerous (EmgD, EIC) to far‐advanced invasive lesions. We further investigated the cell proliferation capacity after siRNA‐mediated KPNA2 knockdown in the human endometrial cancer cell line MFE‐296. KPNA2 silencing led to decreased proliferation of the cancer cells, suggesting interplay of the protein with the cell cycle. Taken together, increased expression of KPNA2 is an independent prognostic marker for poor survival. The mechanism of enhanced nucleocytoplasmic transport by KPNA2 overexpression seems a common event in aggressive cancers since we have shown a significant correlation of KPNA2 expression and tumour aggressiveness in a large variety of other solid tumour entities. Introducing KPNA2 immunohistochemistry in routine diagnostics may allow for the identification of patients who need more aggressive treatment regimens. Copyright

Urodynamic and radiologic results after surgical treatment of female stress urinary incontinence

Between 1985 and 1991, 88 patients underwent abdominal colposuspension and a further 50 were treated with anterior colporrhaphy. Both preoperatively and 6 months after the operation the following were evaluated: the grade of incontinence, the posterior urethral vesical angle measured by voiding cystourethrogram, and the maximum urethral closure pressure (MUCP) at rest and during stress as measured by cystometry. At 1 year the colposuspension patients had a 69% success rate and the cure rate for anterior colporrhaphy was 38%. In postoperatively continent women the urethrovesical junction was significantly better elevated above the lower edge of the symphysis than in patients where the incontinence recurred postoperatively. The higher the urethrovesical junction was suspended, the more the MUCP during stress was increased. Treatment of genuine stress incontinence is best accomplished by retropubic colposuspension, with or without anterior colporrhaphy for coexisting cystocele.

Abstract 3293: p53 suppresses type II endometrial carcinomas in mice and governs endometrial tumour aggressiveness in humans

Type II endometrial carcinomas are a highly aggressive group of tumour subtypes that are frequently associated with inactivation of the TP53 tumour suppressor gene. We show that mice with endometrium-specific deletion of Trp53 initially exhibited histological changes that are identical to known precursor lesions of type II endometrial carcinomas in humans and later developed carcinomas representing all type II carcinoma subtypes. The PI3K-Akt-mTOR signalling pathway was frequently activated in these precursor lesions and tumours, suggesting a genetic cooperation between this pathway and Trp53 deficiency in tumour initiation. Consistent with this idea, immunohistochemical analyses of 521 human endometrial carcinomas identified frequent mTOR pathway activation in type I as well as type II endometrial carcinoma subtypes and mTOR pathway activation and p53 expression each independently predicted poor patient survival. We suggest that molecular alterations in p53 and the PI3K-mTOR pathway play different roles in the initiation of the different endometrial cancer subtypes, but that combined p53 inactivation and PI3K-mTOR pathway activation are unifying pathogenic features among histologically diverse subtypes of late stage aggressive endometrial tumours. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3293. doi:1538-7445.AM2012-3293