Immunoreactivity of p27<Superscript>(Kip1)</Superscript>, cyclin D3, and Ki67 in conventional renal cell carcinoma

The goal of the study was to evaluate expression of the cell-cycle regulatory proteins (p27^(Kip1) and cyclin D3) and proliferation marker Ki67 in normal human kidneys and renal cell carcinoma (RCC) tissues. Intensity of the markers’ expression was prospectively studied and compared between normal and RCC tissue samples. Association was analyzed with cancer clinical parameters. p27^(Kip1) was significantly upregulated in normal compared with in RCC samples. Immunoreactivity of the protein negatively correlated with tumor size and was associated with pathological stage and grade. Patients with symptomatic disease had significantly less marker expression than those with incidentally discovered tumors. Intensity of Ki67 staining positively correlated with primary tumor size and associated with disease stage and grade. Cyclin D3 immunoreactivity positively correlated with tumor size. Loss of p27^(Kip1) expression, pathological stage, grade, and tumor size were risk factors for disease recurrence (P = 0.0072, 0.0011, and 0.0467, and P < 0.0001, respectively) and patient death (P = 0.0021, 0.0106, 0.0151, and 0.0021, respectively). With Cox multivariate analysis loss of p27^(Kip1) expression (hazard ratio 9.3, P = 0.002) and tumor size (hazard ratio 5.9, P = 0.015) were the predictors of cancer-specific survival. In conclusion, intensity of the markers’ expression in RCC is associated with tumour clinical parameters (size, stage, grade, and disease presentation type). Loss of p27^(Kip1) expression is a risk factor for the disease recurrence and cancer-related patient death.     

Expression of p27<Superscript>(Kip1)</Superscript>, cyclin D3 and Ki67 in BPH,prostate cancer and hormone-treated prostate cancer cells

p27^(Kip1), cyclin D3 and Ki67 are the markers of DNA damage and cell proliferation. The goal of the current study was to analyze expression of the markers in benign and malignant prostate cancer tissues. Activity of p27^(Kip1), cyclin D3 and Ki67 was immunohistochemically evaluated in different cells of BPH, prostate cancer (PCa) and hormonally treated prostate cancer (HTPCa) tissues. The tissue samples were derived by means of TURP or radical prostatectomy. Intensity of the expression was compared between the groups, and association was sought with clinical parameters. Total expression of p27^(Kip1) was significantly higher in BPH as compared with PCa. Epithelial marker expression was higher in HTPCa than in PCa. Intensity of the expression in epithelial, vascular and ductal cells was negatively associated with the tumor stage and Gleason grades. Total Ki67 activity was positively correlated with patient age and serum PSA level. There was significantly higher expression in PCa and hormone-escaped PCa (HEPCa) as compared with BPH. Epithelial and vascular marker expression was positively associated with tumor stage and Gleason grades. There was a positive correlation between cyclin D3 and serum PSA level. With the increase of Gleason grades, cyclin D3 expression increased significantly. Expression of p27^(Kip1) negatively correlated with Ki67 and cyclin D3, while the latter two markers correlated positively. p27^(Kip1) is down-regulated, whereas Ki67 and cyclin D3 are up-regulated in PCa. Intensity of the markers’ expression is associated with tumor stage and grades. Hormonotherapy of PCa causes activation of p27^(Kip1). HEPCa is characterized by increased Ki67 expression.     

Absence of the Cell Cycle Inhibitor p27Kip1 Protein Predicts Poor Outcome in Patients With Stage I-III Colorectal Cancer

Background: The p27^Kip1 protein regulates the G1 to S phase transition of cell cycle by binding to and inhibiting the cyclin E/Cdk2 complex. This study explores the prognostic significance of the absence of the p27^Kip1 protein in patients with colorectal cancer (CRC).Methods: Formalin-fixed tumor sections from 124 patients who underwent curative resection for stage I-III CRC were analyzed by immunohistochemistry using MoAb anti-p27^Kip1.Results: Detectable levels of p27^Kip1 protein were found in 86% of tumors. Median follow-up was 55 months. Actuarial 5-year disease-free survival (DFS) and overall survival (OS) were 76% and 85%, respectively, in patients with tumors with p27^Kip1 protein expression and 34% and 40%, respectively, in those whose tumors lacked p27^Kip1 protein expression (P < .001). At multivariate analysis, tumor stage (III vs. I-II) and p27^Kip1 protein status (absence vs. presence) were found to be independent prognostic factors for DFS and OS.Conclusions: Lack of p27^Kip1 protein expression in CRC is a negative prognostic marker and may therefore be useful in selecting early-stage patients more likely to benefit from adjuvant treatment.Presented at the 51st Annual Cancer Symposium of The Society of Surgical Oncology, San Diego, California, March 26–29, 1998.     

High cytoplasmic expression of p27(Kip1) is associated with a worse cancer-specific survival in clear cell renal cell carcinoma

What's known on the subject? and What does the study add? The loss of p27^Kip1 correlates with poor prognosis in various human cancers, and was postulated as a biomarker in RCC. Up to now p27^Kip1 analysis in RCC was focused on its nuclear localization. We confirmed higher p27^Kip1 expression in the nucleus and cytoplasm of RCC and correlated high cytoplasmic p27^Kip1 with an unfavourable clinic and a reduced survival.

OBJECTIVES

• ? To analyse the cytoplasmic and nuclear differences of p27^Kip1 expression and localization in benign and clear cell renal cell carcinoma (ccRCC) with regard to overall survival (OS) and cancer‐specific survival (CSS).
• ? p27^Kip1 is considered to contribute to the progression of ccRCC and is targeted by next generation dual‐therapies.

PATIENTS AND METHODS

• ? In 140 patients, ccRCC and corresponding benign kidney tissue were analyzed for nuclear and cytoplasmic staining of p27^Kip1 by immunohistochemistry using a tissue microarray technique.
• ? Staining intensity and percentage of positive stained cells are given as expression scores. p27^Kip1 expression was categorized as high if ccRCC tissue stained stronger than the respective level of the corresponding benign tissue and categorized as low if ccRCC tissue stained less than or equal to the corresponding benign tissue.
• ? Differences in OS and CSS were analyzed by log‐rank analysis and expression levels were correlated with tumour and patient characteristics using Fisher's exact test.

RESULTS

• ? Cytoplasmatic (mean [sd ]: 13.8% [1.2%] vs 10.7% [1.7%]; P= 0.04) and nuclear (mean [sd ]: 75.6% [2.7%] vs 13.6% [2.1%]; P < 0.001) staining of p27^Kip1 were significantly stronger in ccRCC tissues compared to benign tissue.
• ? High cytoplasmic p27^Kip1 expression was significantly associated with a higher T and N stage, Fuhrman grade and the presence of metastatic disease (P < 0.001).
• ? The median follow‐up time was 38.2 months.
• ? There was no difference in OS between the low and high expression groups, although CSS was significantly lower in patients with high cytoplasmic p27^Kip1 (P < 0.001) and CSS heavily tended to be lower in the nuclear low expression group (P= 0.069).

CONCLUSIONS

• ? High cytoplasmic p27^Kip1 levels in renal cancer tissues are associated with advanced disease and reduced cancer specific survival, whereas low nuclear expression levels appear to be beneficial.
• ? The present study corroborates the consideration of cytoplasmic p27^Kip1 for future diagnostic and targeted therapeutic approaches in RCC establishing a potential protective shift of p27^Kip1 from the cytoplasm to the nucleus.

     

Influence of ischaemia/reperfusion and LFA-1 inhibition on telomere lengths and CDKI genes in ex vivo haemoperfusion of primate kidneys

The telomere (T) length, p21^(WAF1/CIP1) and p27^(Kip1) cyclin-dependent kinase inhibitor (CDKI) genes are the markers of cell senescence and DNA damage. The aim of the study was to determine the influence of renal ischaemia/reperfusion (I/R) and anti-lymphocyte function-associated antigen-1 (LFA-1) monoclonal antibody (mAb) treatment on the value of the above-mentioned markers. Significantly higher levels of p21 and p27 were expressed by the glomeruli (P=0.001 and P=0.0001), tubules (P=0.0065 and P=0.0006), and interstitial cells (P=0.0017 and P=0.0022, respectively) of the xenoperfused kidneys. The mean T length of non-perfused renal specimens (5.56±0.60 kbp) was longer than that of the xenoperfused kidneys (5.46±0.36 kbp) [P= non-significant (NS)]. Addition of anti-LFA-1 mAb did not significantly influence the gene expression profile in the xenoperfused kidneys. The mean T length was longer in the kidneys with anti-LFA-1 mAb than in those without the medication (5.7±0.11 vs 5.13±0.31 kbp) (P=0.0661). Kidney I/R is associated with telomere shortening and an over-expression of p21 and p27 CDKIs, which indicates substantial DNA damage and/or accelerated tissue senescence. Although anti-LFA-1 mAb had some protective effect on the telomeres, it did not influence the gene expression profile in this study.A.B. Chkhotua and H. Schelzig share first authorship     

Increased Expression of Fractalkine is Correlated with a Better Prognosis and an Increased Number of Both CD8<Superscript>+</Superscript> T Cells and Natural Killer Cells in Gastric Adenocarcinoma

Background Fractalkine (CX3CL1) is the only CX3C chemokine that can chemoattract natural killer (NK) cells, CD8⁺ T cells, monocytes, and dendritic cells. Although experimental studies have demonstrated that Fractalkine expression by tumor cells is related to the infiltrating lymphocytes and initiates antitumor immunity, the clinical significance of Fractalkine remains to be elucidated in gastric adenocarcinoma. Methods Tissue sections from 158 patients with curatively resected T2 or T3 gastric adenocarcinoma were immunohistochemically stained for Fractalkine. Furthermore, to evaluate CD8⁺ T cells and NK cells infiltration, antibodies to CD8 and CD57 protein were respectively used for immunohistochemistry. Results A significant direct correlation was observed between the Fractalkine scores and the number of CD8⁺ T cells and NK cells using the Spearman rank correlation coefficient test (P = .0080, .0031, respectively). Furthermore, the high Fractalkine expression group (n = 67) showed a significantly better prognosis than the low Fractalkine expression group (n = 91) regarding the disease-free survival (P = .0016). In a multivariate analysis, the Fractalkine expression was identified as one of the independent prognosticators for disease-free survival (risk ratio, 2.5; P = .0147). Conclusions These data suggest that the expression of Fractalkine by tumor cells enhances the recruitment of CD8⁺ T cells and NK cells and induces both innate and adaptive immunity, thereby yielding a better prognosis in gastric adenocarcinoma. Fractalkine is a new independent predictor of the prognosis and can be a novel candidate for development of a more effective therapeutic strategy for gastric adenocarcinomas.     

A comparison of the vascular density of VEGF expression with microvascular density determined with CD34 and CD31 staining and conventional prognostic markers in renal cell carcinoma

Aim The aim of this study was to compare the vascular density of Vascular endothelial growth factor (VEGF) expression with microvascular density determined by CD34 and CD31 with conventional prognostic parameters. Methods The study involved 50 renal cell carcinoma (RCC) cases. VEGF, CD34, and CD31 were stained by immunohistochemistry, and then preparations were evaluated by two pathologists under light microscopy. The whole tumor area was scrutinized in all the sections. In the evaluation of VEGF, due to the lack of homogenous staining within the tumor, two parameters, distribution and intensity of expression, were evaluated semiquantitively. In the evaluation of microvascular density with CD34 and CD31 staining, three hot areas with the highest density were determined. In ×200 magnification of these areas, on a single plane, the quantity of vascular structures with lumens was determined. Results Intensity of VEGF Expression was higher in papillary type carcinoma of kidney parenchyma (P = 0.014) and it was significantly correlated with tumor stage (P = 0.013), survival time (P = 0.01), and tumor size (P = 0.035). Distribution of VEGF expression was also higher in papillary RCC (P = 0.055) and it was significantly correlated with tumor stage (P = 0.043) and tumor size (P = 0.039). Vascular density determined with CD34 staining was higher in conventional RCC (P < 0.05); in addition, it was significantly correlated with distribution and intensity of VEGF expression (P < 0.05) and tumor stage (P < 0.05). Vascular density determined with CD31 staining was not significantly correlated with tumor type, tumor stage, nuclear grade, and survival time. Conclusions Intensity and distribution of VEGF were higher in papillary RCC. Both parameters were significantly correlated with tumor size, stage, and vascular density determined with CD34 staining. Intensity of VEGF was also significantly correlated with capsule invasion. Vascular density determined with CD34 staining, however, was higher in conventional RCC, and it was correlated with tumor size and stage.     

Immunohistochemically Detected Expression of p27Kip1 and Skp2 Predicts Survival in Patients with Intrahepatic Cholangiocarcinomas

In intrahepatic cholangiocarcinomas (ICCs), the prognostic significance of p27^Kip1, a cyclin-dependent kinase inhibitor, remains controversial, and there have been no studies of degradation pathway associated proteins, S-phase kinase-interacting protein (Skp2), and Jun activation domain-binding protein-1 (Jab1). In the present study of 74 patients with ICC–mass forming type (ICC-MF) undergoing radical surgery, we determined immunohistochemical expression of p27^Kip1, Skp2, and Jab1 and examined relationships with clinicopathologic findings and patient survival. On the basis of the average of labeling indices, we set cutoff values to define high and low expressors and divided the cases into two groups. A statistically significant correlation was found between low p27^Kip1 expression and lymph node metastasis (P = .009). Patient survival in the low p27^Kip1 expression group (n = 25) was also significantly worse than that in the high p27^Kip1 expression group (n = 49, P = .0007). A significant inverse correlation was found between p27^Kip1 and Skp2 expression (P = .016). High Skp2 expression (n = 36) was significantly associated with poor prognosis (P = .0046). High Jab1 expression was observed in 32 cases, but there was no statistically significant relationship with clinicopathologic findings or patient survival. The multivariate analysis revealed that low p27^Kip1 and high Skp2 expression are independent and significant factors of poor prognosis. The results suggest that low p27^Kip1 and high Skp2 expression are associated with aggressive tumor behavior, and these cell-cycle regulators are useful markers to predict outcome of patients with ICC-MF.     

Estrogen and ghrelin decrease cytoplasmic expression of p27<Superscript>kip1</Superscript>, a cellular marker of ageing,in the striated anal sphincter and levator muscle of ovariectomized rats

A study was carried out to investigate the effect of estrogen and/or ghrelin on the cellular marker of ageing, p27^kip1, in pelvic floor muscles of ovariectomized rats. Virgin Wistar rats (13 months old) underwent ovariectomy followed (1 month) by 42 daily intraperitoneal 17-β estradiol (10 μg/kg), ghrelin (2 μg/kg), both hormones, or placebo vehicle (n=6×4 groups). Six more age-matched animals underwent sham surgery without ovariectomy. Cytoplasmic expression of p27^kip1 in the striated urethral and anal sphincters and levator muscle was measured by Western blot analysis in all animals (n=30). p27^kip1 signal intensity significantly increased postovariectomy in all muscles compared to sham animals. In the anal sphincter and levator, signal intensity decreased to sham levels with ghrelin or estrogen and decreased further after estrogen or ghrelin and estrogen/ghrelin administration. Urethral sphincter signal intensity decreased without reaching sham levels after drug administration. Estrogen and/or ghrelin replacement reverses the ovariectomy-induced exacerbation of biochemical cellular ageing in the anal sphincter and levator muscle of middle-aged rats.     

Comparison of Uptake Characteristics and Prognostic Value of <Superscript>201</Superscript>Tl and <Superscript>18</Superscript>F-FDG in Esophageal Cancer

Background Patients with esophageal cancer often undergo ²⁰¹Tl myocardial imaging for preoperative risk evaluation, thereby providing an excellent opportunity to assess tumor handling of ²⁰¹Tl. We thus compared the characteristics of ²⁰¹Tl and ¹⁸F-FDG uptake by esophageal cancer and further investigated their prognostic values. Methods The study included 100 newly diagnosed esophageal cancer patients who underwent preoperative ²⁰¹Tl SPECT and ¹⁸F-FDG PET exams. Tumor to mediastinal uptake (T/M) ratio and retention index (RI) of ²⁰¹Tl, tumor ¹⁸F-FDG pSUV, tumor size, location, and stage were assessed. Survival analysis was performed for disease-free survival using the Kaplan–Meier method. Cox proportional hazard models were used to determine independent risk factors. Results ²⁰¹Tl SPECT and ¹⁸F-FDG PET visualized the primary tumor in 85/100 (85.0%) and 91/100 (91.0%) patients, respectively (p = 0.03). There were close correlations between early and delayed ²⁰¹Tl T/M ratios (r = 0.83, p < 0.0001) and between T/M ratios and ¹⁸F-FDG pSUV (r = 0.56 and 0.57, respectively, both p < 0.0001). Both T/M ratios and ¹⁸F-FDG pSUV correlated significantly with tumor stage (ρ = 0.45, 0.40, and 0.59, respectively, all p < 0.0001). Survival analysis revealed tumor size, ²⁰¹Tl negative tumors, ¹⁸F-FDG negative tumors, delayed ²⁰¹Tl T/M ratio, RI, stage, and ¹⁸F-FDG pSUV to be significant univariate predictors for disease-free survival. Multivariate survival analysis showed stage (p = 0.02) to be a significant independent prognostic predictor. Conclusions In patients with esophageal cancer, assessment of tumor ²⁰¹Tl uptake, as with ¹⁸F-FDG, may provide potentially useful information regarding tumor characteristics. Presented in part at the 51st Annual Meeting of the Society of Nuclear Medicine, Philadelphia, PA, USA, June 19–23, 2004.     

Prognostic significance of thrombocytosis in renal cell carcinoma patients

Background: Thrombocytosis has been reported in many types of malignancies and has been studied as a prognostic factor. In the present study, we examined the incidence of thrombocytosis in patients with renal cell carcinoma (RCC) in order to evaluate the prognostic value of thrombocytosis. Methods: One hundred and ninety‐six patients treated by radical nephrectomy for RCC were enrolled in this study. We divided the patients into a normal platelet count group and a thrombocytosis group according to the presurgical platelet count. The two groups were compared pathologically and clinically, including prognosis. Results: Thrombocytosis was present in 16 patients (8.2%). Platelet counts had normalized after nephrectomy in all patients with thrombocytosis. There was no correlation between histological type or grade and thrombocytosis. However, there were correlations between thrombocytosis and tumor size and tumor stage. Patients with thrombocytosis had a worse prognosis than patients without thrombocytosis (P = 0.0028). When adjusted for stage or tumor size, the correlation was limited to low stage (stage 1 + 2: P = 0.0041, stage 3 + 4: P = 0.2983) or small tumors (tumor size: ≤4 cm, P = 0.0021; 4–7 cm, P = 0.0142; >7 cm, P = 0.8158). Conclusion: Thrombocytosis is an inexpensive and easy tool with which to evaluate the prognosis of RCC patients in daily medical practice.     

KB-R9032, newly developed Na<Superscript>+</Superscript>/H<Superscript>+</Superscript> exchange inhibitor,attenuates reperfusion-induced arrhythmias in isolated perfused rat heart

Purpose This study was conducted to elucidate the effects of KB-R9032, a newly developed Na⁺-H⁺ exchange inhibitor, on reperfusion-induced ventricular arrhythmia in the isolated perfused rat heart.Methods Male Wistar rat hearts (n = 48; 12 for each group) were perfused with modified Krebs-Ringers solution equilibrated with 5% carbon dioxide in oxygen by means of the Langendorff technique. An occluder was placed around the left anterior descending coronary artery (LAD). Heart rate, coronary flow, and ECG were monitored. Drug-free perfusate was used for 10min before switching to a perfusate containing various concentrations of KB-R9032. The added concentrations of KB-R9032 varied in the range of 0 (control) to 1 × 10^–5mol·l^–1. Each heart was subjected to regional ischemia (occlusion of LAD for 11min) and to 3min of reperfusion (release of the ligation).Results In the control group, reperfusion-induced ventricular fibrillation (VF) occurred in 91.7%, and the duration was 158.2 ± 14.4s (mean ± SEM); however, 1 × 10^–7, 1 × 10^–6, and 1 × 10^–5mol·l^–1 KB-R9032 reduced the incidence of VF to 75.0%, 42.9%, and 6.7%, respectively (P < 0.05 at 1 × 10^–5mol·l^–1 of KB-R9032) and reduced the duration of VF to 64.8 ± 22.1, 16.8 ± 10.1, and 1.2 ± 1.2s, respectively (P < 0.05 at 1 × 10^–6 and 1 × 10^–5mol·l^–1 of KB-R9032).Conclusion It was shown in this study that the Na⁺/H⁺ exchange inhibitor KB-R9032 suppresses reperfusion arrhythmias in the ischemia-reperfusion model of isolated rat heart.     

Induction of cell cycle arrest and apoptosis in human prostate carcinoma cells by a recombinant adenovirus expressing p27(Kip1)

BACKGROUND: Adp27(Kip1), a recombinant adenovirus, was evaluated for expression of p27, a cyclin-dependent kinase inhibitor (CDKI) and tumor suppressor protein, in human prostate carcinoma cells. Effects of p27(Kip1) on cell cycle and apoptosis were analyzed. METHODS: We evaluated the effects of overexpression of p27(Kip1) in the human prostate carcinoma cell lines LNCaP, DU-145, and PC-3 in vitro and in vivo. Growth curve studies, cell cycle analysis, terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL), and annexin V-fluorescein isothiocyanate apoptosis analyses were conducted to determine effects of p27(Kip1) on cell cycle. CDKI activity assays and Western blots were conducted to determine presence/activities of CDKIs. RESULTS: Adp27(Kip1)-induced protein levels increased in a dose-dependent manner; p27(Kip1) protein was detected within 6 hr of infection with Adp27(Kip1) and remained stable for at least 48 hr. The activities of Cdk2, Cdk4, and Cdc2 kinases were inhibited 24 hr after infection with Adp27(Kip1). Bromodeoxyuridine incorporation demonstrated a dose-dependent decrease in S-phase cells 24 hr postinfection. TUNEL analysis revealed an induction of apoptosis (10 pfu/cell) within 48 hr of infection in all cell lines. Growth curve analyses demonstrated that Adp27(Kip1) infection inhibited proliferation of all cell lines tested and decreased cell numbers for Adp27(Kip1)-infected LNCaP and PC-3 cells by 96 hr. Cell cycle analysis of DNA content demonstrated an accumulation of cells in G0/G1-phase 24-120 hr after Adp27(Kip1)-infection. In vivo studies demonstrated a reduction in LNCaP xenograft tumor growth rates in mice injected with Adp27(Kip1). CONCLUSION: Exogenous p27(Kip1) overexpression results in cell cycle regulation in the human prostate carcinoma cell lines tested, representing the first use of this vector on prostate cancer cell lines in vitro and in vivo. Moreover, p27(Kip1) expression is associated with an increase in early apoptosis, which represents a recently discovered function for this protein. It also represents the first time this association has been observed in prostate carcinoma cell lines. This study provides support for the further development of Adp27(Kip1) as a potential therapeutic vector in the treatment of adenocarcinoma of the prostate.     

HPV DNA is Associated with a Subset of Schneiderian Papillomas but Does not Correlate with p16<Superscript>INK4a</Superscript> Immunoreactivity

This study investigated the role of human papillomavirus (HPV) in Schneiderian papillomas (SPs) to determine whether HPV is associated with the pathogenesis of particular histologic subtypes and whether p16^INK4a can be used as a surrogate marker for HPV detection. Twenty-seven papilloma specimens (19 inverted [IPs], 6 exophytic [EPs], 1 oncocytic [OP] and 1 mixed) were collected from 23 patients. Purified SP DNA extracts were tested for HPV by PCR using GP5 +/GP6 + primers; HPV genotyping was performed by dot blot hybridization. PCR positive specimens were screened for HPV by biotinyl-tyramide-based chromogenic in situ hybridization (CISH). Immunohistochemsistry (IHC) for the HPV L1 capsid protein and for p16^INK4a was performed on all specimens. HPV was detected by PCR in 16/27 (59.3%) SPs; 9/19 (47.4%) IPs; 6/6 (100%) EPs [p = 0.051], and 1/1 (100%) mixed SP. HPV was not detected in the single OP. High risk genotypes were detected in 4/9 IPs (44.4%) and 0/6 EPs (0%) [p = 0.10]. Seven of 16 PCR positive SPs were also CISH positive for HPV: 5/6 EPs (83.3%) and 1/9 IP (11.1%) [p = 0.01]. IHC for the L1 capsid protein was positive in 2 SPs (1 EP and 1 mixed). p16^INK4a staining was seen in 14/16 (87.5%) PCR positive SPs and in 10/11 (90.9%) PCR negative SPs (p = 1.00). In summary, this study demonstrates a strong association between HPV and EPs, however, its role in IPs remains less well-defined. Further, p16^INK4a is not a useful surrogate marker for HPV detection across the various SPs.     

Chondrocyte p21<Superscript>WAF1/CIP1</Superscript> Expression Is Increased by Dexamethasone but Does Not Contribute to Dexamethasone-Induced Growth Retardation In Vivo

It has been shown that cell cycle genes play an important role in the coordination of chondrocyte proliferation and differentiation. The inhibitory effects of glucocorticoids (GCs) on chondrocyte proliferation are consistent with GCs disrupting cell cycle progression and promoting cell cycle exit. Cyclin-dependent kinase inhibitors (CDKIs) force cells to exit the cell cycle and differentiate, and studies have shown that expression of the CDKI p21^CIP1/WAF1 is increased in terminally differentiated cells. In this study, p21 mRNA and protein expression was increased during chondrocyte differentiation and after exposure to dexamethasone (Dex, 10⁻⁶ M) in murine chondrogenic ATDC5 cells. In 4-week-old mice lacking a functional p21 gene, Dex caused a reduction in body weight compared to saline control null mice, but this was consistent with the reduction in body weight observed in Dex-treated wild-type littermates. In addition, p21 ablation had no effect on the reduction in width of the growth plate or reduced mineral apposition rate in Dex-treated mice. However, an alteration in growth rate and epiphyseal structure is evident when comparing p21^−/− and wild-type mice. These findings suggest that p21 does not directly contribute to GC-induced growth retardation in vivo but is involved in the maintenance of the growth plate.     

Anomalous overexpression of p27(Kip1) in sporadic pancreatic endocrine tumors

BACKGROUND: Little is known about the cellular defects and molecular mechanisms leading to pancreatic endocrine tumors (PETs). p27(Kip1) is a universal cyclin-dependent kinase inhibitor (CDKI), which acts as a tumor suppressor and a negative regulator of cell cycle. From previous reports, quiescent cells show high levels of p27(Kip1) expression while neoplastic and proliferating cells show no detectable p27(Kip1) expression. We hypothesize that in malignant sporadic PETs, p27(Kip1) expression would be decreased compared with benign PETs and normal pancreatic tissue. METHODS: Western analysis was performed on 28 PETs (7 malignant, 21 benign), 2 nonendocrine cell lines, and 5 endocrine cell lines. Signal intensities were quantitated using densitometry and standardized to normal pancreas. RESULTS: Unexpectedly, increased p27(Kip1) expression as compared with control was seen in both benign and malignant tumors, as well as in all four pancreatic islet tumor cell lines, but not fibroblast or pituitary cell lines, evaluated. There was no difference in p27(Kip1) level between benign and malignant tumors. CONCLUSION: This represents the first report of anomalous p27(Kip1) overexpression in sporadic PETs, and is part of a growing literature describing the paradoxical overexpression of p27(Kip1) in human tumors that includes other endocrine tumors. These studies suggest a unique molecular pathway leading to endocrine tumorigenesis.     

P27Kip1 and Ki-67 expression analysis in transitional cell carcinoma of the bladder

P27^Kip1 protein is a cell cycle inhibitor which blocks the transition of cells from G1 to S phase, while Ki-67 is the most specific marker of proliferative activity. Both proteins are independent predictors of clinical outcome in various neoplasms. The aim of the study was to assess the prognostic value of p27^Kip1 and Ki-67 expression in urothelial bladder tumours. P27^Kip1 and Ki-67 expressions were evaluated immunohistochemically in archival samples of 45 superficial and 26 invasive transitional cell carcinomas obtained by a transurethral resection. In the patients with superficial tumours, disease-free survival (DFS) was positively influenced by good histological differentiation as well as by concurrent high p27^Kip1 and low Ki-67 expression. Multivariate analysis has confirmed that tumour grade and p27^Kip1/Ki-67 status were independent predictors of DFS (p=0.028 and p=0.029, respectively). P27^Kip1 or Ki-67 expressions did not influence overall survival. We conclude that a variable combined of p27^Kip1 and Ki-67 expressions is a better predictor of DFS in superficial bladder tumours than either protein alone.