Reduced expression of the cell-cycle inhibitor p27Kip1 is associated with progression and lymph node metastasis of gastric carcinoma

PIM3 Kinase: A Promising Novel Target in Solid Cancers

PIM3 (provirus-integrating Moloney site 3) is a serine/threonine kinase and belongs to the PIM family (PIM1, PIM2, and PIM3). PIM3 is a proto-oncogene that is frequently overexpressed in cancers originating from endoderm-derived tissues, such as the liver, pancreas, colon, stomach, prostate, and breast cancer. PIM3 plays a critical role in activating multiple oncogenic signaling pathways promoting cancer cell proliferation, survival, invasion, tumor growth, metastasis, and progression, as well as chemo- and radiation therapy resistance and immunosuppressive microenvironment. Genetic inhibition of PIM3 expression suppresses in vitro cell proliferation and in vivo tumor growth and metastasis in mice with solid cancers, indicating that PIM3 is a potential therapeutic target. Although several pan-PIM inhibitors entered phase I clinical trials in hematological cancers, there are currently no FDA-approved inhibitors for the treatment of patients. This review provides an overview of recent developments and insights into the role of PIM3 in various cancers and its potential as a novel molecular target for cancer therapy. We also discuss the current status of PIM-targeted therapies in clinical trials.

Successful development of squamous cell carcinoma and hyperplasia in RGEN-mediated p27 KO mice after the treatment of DMBA and TPA

To evaluate the carcinogenicity of p27 knockout (KO) mice with RNA-guided endonuclease (RGENs)-mediated p27 mutant exon I gene (IΔ), alterations in the carcinogenic phenotypes including tumor spectrum, tumor suppressor proteins, apoptotic proteins and cell cycle regulators were observed in p27 (IΔ) KO mice after treatment with 7,12-Dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)(DT) for 5 months. The target region (544~571 nt) in exon I of the p27 gene was successfully disrupted in p27 (IΔ) KO mice using the RGEN-induced non-homologous end joining (NHEJ) technique. After DT exposure for 5 months, a few solid tumors (identified as squamous cell carcinoma) developed on the surface of back skin of DT-treated p27 (IΔ) KO mice. Also, squamous cell hyperplasia with chronic inflammation was detected in the skin dermis of DT-treated p27 (IΔ) KO mice, while the Vehicle+p27 (IΔ) KO mice and WT mice maintained their normal histological skin structure. A significant increase was observed in the expression levels of tumor suppressor protein (p53), apoptotic proteins (Bax, Bcl-2 and Caspase-3) and cell-cycle regulator proteins (Cyclin D1, CDK2 and CDK4) in the skin of DT-treated p27 (IΔ) KO mice, although their enhancement ratio was varied. Taken together, the results of the present study suggest that squamous cell carcinoma and hyperplasia of skin tissue can be successfully developed in new p27 (IΔ) KO mice produced by RGEN-induced NHEJ technique following DT exposure for 5 months.

Characterization of oncogene suppressor marker expression in patients with submucosal gastric carcinoma

The aim of the present study was to determine the clinical significance of p53 and p21^ras p21^wafl, p27^kip1 and p16^ink4a expression in cases of early gastric cancer. A total of 81 patients who had undergone gastrectomy with D2 lymphadenectomy between 1971 and 2004 were retrospectively investigated. The immunohistochemical expression of p21^ras, p53, p21^waf1/cip1, p27^kip1 and p16^ink4a in the tissues was evaluated. In normal, metaplastic and tumoral mucosa, p53 was positive in 53, 87.3, and 87.1% of the cases, respectively. In the same tissues, p21^ras was positivE in 85.3, 86 and 96.8%, respectively. Positivity FOR p16^ink4a was DETECTED IN 46.3, 91.1 and 86% OF THE CASES, respectively, WHEREAS p27^kip1 WAS positiVE IN 60, 94.7 and 95.3%, and p21^wafl/cip1 WAS positivE IN 32.4, 72.7 and 71.4% OF THE CASES, respectively. All THE tumors WERE positive for p53. Tumors with lymph node invasion presented WITH OVERexpression (+4) of p53 in 47% of the cases VS. 17% OF patients who DID not HAVE lymph node involvement. THEREFORE, higher expression of p53, p21^ras and p21^wafl/cip1 IN the tumor exhibited a statistically significant association with lymph node involvement.

Clinical significances of p27 in digestive tract cancers: a comprehensive analysis on immunohistochemistry staining, published literatures, microarray and RNA-seq data

In the present study, we conducted a comprehensive analysis on the clinical roles of p27 protein and p27 gene in digestive tract cancers (DTCs). First, we performed immunohistochemistry staining and found that p27 protein was down-regulated in DTCs. Then we collected 62 publications and calculated the combined hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (95% CIs) to clarify the relationships of p27 protein expression with prognoses and clinicopathological parameters. The overall HRs indicated that the down-regulated p27 protein was an independent prognostic biomarker for overall survival (HR: 1.58, 95% CI: 1.38-1.81, P < 0.0001) but not for disease-free survival and cancer-specific survival. The combined ORs indicated that a low expression of p27 protein was positively related to lymph node metastasis (OR: 2.15, 95% CI: 1.57-2.96, P < 0.0001), distant metastasis (OR: 2.02, 95% CI: 1.12-3.63, P = 0.019) and pathology grading (OR: 2.14, 95% CI: 1.75-2.62, P < 0.0001). Additionally, 60 DTCs-related microarray and RNA-seq datasets were obtained to investigate the expression level and clinical value of p27 gene in DTCs patients. We found that the expression level of p27 gene in DTCs was similar to that in normal controls. And no significant associations of p27 gene expression with prognoses and clinicopathological factors were observed. In conclusion, according to our results, it was p27 protein, but not p27 gene, that can function as an effective biomarker to predict the clinical outcome in patients with DTCs. The down-regulation of p27 protein in DTCs may not result from the altered expression of p27 gene.

MicroRNA-340 Inhibits Tumor Cell Proliferation and Induces Apoptosis in Endometrial Carcinoma Cell Line RL 95-2

BACKGROUND The purpose of our study was to investigate the functional role of microRNA-340 (miR-340) in endometrial carcinoma (EC). MATERIAL AND METHODS Human EC cell line RL 95-2 was transfected with miR-340 mimics, inhibitors, or controls. After 48 h of transfection, the cell viability was determined by 3-(4, 5-dimethyl-2- thiazolyl)-2, 5-diphenyl -2-H-tetrazolium bromide (MTT) assay. The BrdU assay and apoptosis assay were performed to determine the effects of miR-340 mimics or inhibitors on cell proliferation and apoptosis, respectively. The underlying mechanisms involved in cell proliferation and apoptosis were explored by measuring the protein levels of cell cycle regulators (p27 kinase inhibition protein (KIP) 1 and p21) and apoptosis-related factors (B-cell lymphoma-2 (Bcl-2), Bax, pro-Caspase 3, and active-Caspase-3). RESULTS Overexpression of miR-340 significantly inhibited the cell viability (P<0.05) and cell proliferation (P<0.01) of RL 95-2 cells compared with the control group, but increased the apoptosis (P<0.01). However, suppression of miR-340 had opposite results. Moreover, the protein levels of p27 KIP1, Bax, pro-Caspase 3, and active-Caspase-3 were significantly increased by overexpression of miR-340 but were statistically decreased by suppression of miR-340. Contrary results were found in the protein levels of Bcl-2. However, no significant differences were found in p21 expression. CONCLUSIONS MiRNA-340 acts as an anti-oncogene in EC cell line RL 95-2 by inhibition of tumor cell proliferation and induction of apoptosis.

Identification of biomarkers for diagnosis of gastric cancer by bioinformatics

BACKGROUND

We aimed to discover potential gene biomarkers for gastric cancer (GC) diagnosis.

MATERIALS AND METHODS

Genechips of 10 GC tissues and 10 gastric mucosa (GM, para-carcinoma tissue, normal control) tissues were generated using an exon array of Affymetrix containing 30,000 genes. The differentially expressed genes (DEGs) between GC tissues and normal control were identified by the Limma package and analyzed by hierarchical clustering analysis. Gene ontology (GO) and pathway enrichment analyses were performed for investigating the functions of DEGs. Receiver operating characteristics (ROC) analysis was performed to measure the effects of biomarker candidates for diagnosis of GC.

RESULTS

Totals of 896 up-regulated and 60 down-regulated DEGs were identified to be differentially expressed between GC samples and normal control. Hierarchical clustering analysis showed that DEGs were highly differentially expressed and most DEGs were up-regulated. The most significantly enriched GO-BP term was revealed to be mitotic cell cycle and the most significantly enriched pathway was cell cycle. The intersection analysis showed that most significant DEGs were cyclin B1 (CCNB1) and cyclin B2 (CCNB2). The sensitivities and specificities of CCNB1 and CCNB2 were both high (p<0.0001). Areas under the ROC curve for CCNB1 and CCNB2 were both greater than 0.9 (p<0.0001).

CONCLUSIONS

CCNB1 and CCNB2, which were involved in cell cycle, played significant roles in the progression and development of GC and these genes may be potential biomarkers for diagnosis and prognosis of GC.

Immunohistochemical expression of p27(kip1) in metastatic laryngeal squamous cell carcinoma

PURPOSE

Laryngeal squamous cell carcinoma (LSCC) is an interesting diagnostic and therapeutic issue. The diagnostic delay is mainly a consequence of the lack of evident symptoms in the early stage of the disease. The purpose of current studies was the evaluation of the expression of p27(kip1) in primary and metastatic LSCC in correlation with patients' clinicopathological data.

MATERIAL/METHODS

The indirect immunohistochemical studies were performed on the series of 60 sections (primary tumor: 20 cases of N(0) and 20 cases of N(+), and nodal meta: 20 cases), using primary antibody against p27(kip1) [clone 1B4]. The expression of analyzed protein was performed using automated morphometric methods.

RESULTS

The p27(kip1) nuclear expression was found in 100% (40/40) cases of primary tumor, and in 85% (17/20) cases of SCC meta at lymph nodes. In primary LSCC N(0) the expression of p27(kip1) was significantly higher compared to N(+) cases (p=0.036672). However, the p27(kip1) expression in SCC metastases was higher compared to the primary SCC. Moreover, the analyses based on the classification trees revealed the cutoff p27(kip1) expression in primary LSCC (IRS ≤ 76) which was characteristic for N(+) patients. Consequently, our analysis revealed that high expression of p27(kip1) (IRS>76) was characteristic for N(0) patients.

CONCLUSIONS

Our results suggest that p27(kip1) might be useful prognostic factor of metastatic potential in laryngeal squamous cell carcinoma.

Androgen receptor may be responsible for gender disparity in gastric cancer

Men are at a higher risk of developing gastric cancer than women. However, the exact mechanisms responsible for the gender differences remain unclear. Recently, a number of epidemiological and genotyping studies have attributed the gender disparity in male-predominant cancers to the disruption of androgen receptor (AR) homeostasis. Moreover, previous data indicated that AR expression is an independent unfavorable prognostic factor in gastric cancer, suggesting that AR may play an important role in gastric carcinogenesis. In addition, mounting evidence suggests that AR is involved in many signaling pathways associated with gastric carcinogenesis. On the basis of the aforementioned evidence, we postulate that AR exhibits oncogenic properties in gastric cancer via several possible mechanisms, which may partly explain the higher prevalence of gastric cancer among males.

Losses of chromosome 5q and 14q are associated with favorable clinical outcome of patients with gastric cancer

PURPOSE

To improve the clinical outcome of patients with gastric cancer, intensified combination strategies are currently in clinical development, including combinations of more extensive surgery, (neo)adjuvant chemotherapy, and radiotherapy. The present study used DNA copy number profiling to identify subgroups of patients with different clinical outcomes. We hypothesize that, by identification of subgroups, individual treatment strategies can be selected to improve clinical outcome and to reduce unnecessary treatment toxicity for patients with gastric cancer.

EXPERIMENTAL DESIGN

DNA from 206 gastric cancer patients was isolated and analyzed by genomewide array comparative genomic hybridization. DNA copy number profiles were correlated with lymph node status and patient survival. In addition, heat shock protein 90 (HSP90) expression was analyzed and correlated with survival in 230 gastric cancer patients.

RESULTS

Frequent (>20%) DNA copy number gains and losses were observed on several chromosomal regions. Losses on 5q11.2-q31.3 and 14q32.11-q32.33 (14% of patients) were correlated with good clinical outcome in univariate and multivariate analyses, with a median disease-free survival interval of 9.2 years. In addition, loss of expression of HSP90, located on chromosome 14q32.2, was correlated with better patient survival.

CONCLUSION

Genomewide DNA copy number profiling allowed the identification of a subgroup of gastric cancer patients, marked by losses on chromosomes 5q11.2-q31.3 and 14q32.11-q32.33 or low HSP90 protein expression, with an excellent clinical outcome after surgery alone. We hypothesize that this subgroup of patients most likely will not benefit from (neo)adjuvant systemic treatment and/or radiotherapy, whereas anti-HSP90 therapy may have clinical potential in patients with HSP90-expressing gastric cancer, pending validation in an independent dataset.

Gastric adenocarcinoma and Helicobacter pylori: correlation with p53 mutation and p27 immunoexpression

INTRODUCTION

Helicobacter pylori infection is an established risk factor for gastric cancer development, but the exact underlying mechanism still remains obscure. The inactivation of tumor suppressor genes such as p53 and p27(KIP1) is a hypothesized mechanism, although there is no consensus regarding the influence of H. pylori cagA(+) in the development of these genetic alterations.

GOALS

To verify the relationship among H. pylori infection, p53 mutations and p27(Kip1) Protein (p27) expression in gastric adenocarcinomas (GA) seventy-four tissues were assayed by PCR for H. pylori and cagA presence. Mutational analysis of p53 gene was performed by single-strand conformation polymorphism (SSCP). Seventy tissues were analyzed by an immunohistochemical method for p27 expression.

RESULTS

From the samples examined, 95% (70/74) were H. pylori positive, 63% cagA(+). Altered p53 electrophoretic mobility was found in 72% of cases and significantly more frequent in the presence of cagA. Considerable reduction in p27 expression (19%) was found with a tendency for association between cagA(+) and p27(-), although the results were not statistically significant. Concomitant alterations of both suppressor genes were detected in 60% of cases. In the cases cagA(+), 66.7% of them had these concomitant alterations.

CONCLUSIONS

The data suggest that H. pylori cagA(+) contributes to p53 alteration and indicate that concomitant gene inactivation, with reduced p27 expression, may be a mechanism in which H. pylori can promote the development and progression of gastric cancer.

Endocrine dysfunction in p27Kip1 deficient mice and susceptibility to Wnt-1 driven breast cancer

The cyclin-dependent kinase (Cdk) inhibitor p27(Kip1) (p27) is a marker of prognosis in many cancers, including breast cancer. Low p27 expression correlates with poor prognosis, especially in hormone receptor positive breast tumors. This association suggests a role for p27 in hormone-dependent cancer. We used the Wnt-1 transgenic mouse model to further explore the role of p27 in hormone-driven breast cancer. We found that p27 deficiency did not alter breast cancer rate in either male or female Wnt-1 mice. However, we did find p27-/- females had reduced levels of serum progesterone (P) and increased variability in estradiol (E), which could have affected their cancer susceptibility. To equalize hormone levels, an additional cohort of Wnt-1 female mice was ovariectomized and implanted with slow release pellets of E and P. Although this treatment did not alter the breast cancer rate, it did accelerate the development of pituitary and gastric tumors in p27-/- mice. This study shows that while not a significant inhibitor of Wnt-1-driven breast cancer, p27 inhibits gastric tumors, whose latency is modulated by sex steroids.

Cyclin D1 and p27 expression as prognostic factor in papillary carcinoma of thyroid: association with clinicopathological parameters

AIM

To determine the prognostic value of cell cycle regulators cyclin D1 and p27 for papillary thyroid carcinomas.

METHODS

Analysis included 180 patients with papillary thyroid carcinoma who underwent surgery at Split University Hospital Center between 1999 and 2001. Clinical data were obtained from clinical charts and histopathology reports. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissue by antibody p27 and cyclin D1. Quantification was based on the intensity and distribution of nuclear staining.

RESULTS

Univariate analysis showed that sex (P=0.019) and capsular invasion (P=0.010) were significant predictors of lymph node metastases, whereas age (P=0.96), histopathological variant (P=0.075), size (P=0.556) and multifocality (P=0.131) were not. Univariate analysis also showed that overexpression of cyclin D1 (P<0.001) and underexpression of p27 (P<0.001) predicted lymph node metastases in papillary thyroid carcinomas. There was a significant correlation between cyclin D1 (P=0.024) and p27 (P=0.029) expression in two prognostic groups of low and high risk. Low risk group was cyclin D1 negative and p27 positive, while high risk group was cyclin D1 positive and p27 negative. Multivariate analysis confirmed that sex (P=0.041), capsular invasion (P=0.027), and p27 (P<0.001) were strong independent predictors of lymph node metastases in the high-risk group.

CONCLUSIONS

Immunohistochemical analysis of p27 expression may be a valuable tool for identifying risk of lymph node metastases and more aggressive behavior of papillary thyroid carcinoma.

Cytogenetic and molecular aspects of gastric cancer: clinical implications

Gastric cancer is of major importance world-wide being the second most common cause of cancer-related death in the world. According to Lauren's histological classification gastric cancer is divided in two groups, the better differentiated intestinal carcinomas and the poorly differentiated diffuse-type cancers. The genetic changes underlying the initiation and progression of gastric cancer are not well defined. Gastric carcinogenesis is a multistep process involving a number of genetic and epigenetic factors. Although it has been proposed that different genetic pathways exist for differentiated and undifferentiated carcinomas, the two histological subtypes of gastric cancer share some common genetic alterations. Currently, tumor histology and pathologic stage are the major prognostic variables used in the clinical practice for gastric cancer patients. However, it is known that tumors with similar morphology may differ in biological aggressiveness, prognosis and response to treatment. Molecular genetic analysis of gastric cancer revealed a number of associations of certain genetic changes with pathological features, tumor biological behavior and prognosis of gastric cancer patients, suggesting that these genetic abnormalities might play an important role in gastric tumorigenesis. Increasing evidence suggests that the molecular genetic changes could be helpful in the clinical setting, contributing to prognosis and management of patients. Regarding epigenetic events in gastric tumorigenesis, a number of methylating markers have been proposed for risk assessment, prognostic evaluation and as therapeutic targets. However, further research is required in order to systematically investigate the genetic changes in gastric cancer estimating also their usefulness in the clinical practice. A good understanding of the genetic changes underlying gastric carcinogenesis may provide new perspectives for prognosis and screening of high risk individuals. Some of the genetic alterations could definitely improve tumor classification and management of gastric cancer patients. Also, based on molecular data identified in gastric cancer novel therapeutics might help to improve the treatment of this disease.

Immunohistochemical expression of cell-cycle proteins in gastric precancerous lesions

BACKGROUND

The early indicator for the subject predisposed to gastric cancer is abnormal proliferation of gastric epithelial cells, such as atrophic gastritis (AG), intestinal metaplasia (IM), and dysplasia, which have been considered as precancerous lesions of gastric cancer. To determine whether p53 protein, cyclins D1, and D3, and p27(kip1) play a role in the carcinogenesis pathway of gastric cancer, we performed an immunohistochemical study of their expression in gastric precancerous lesions.

METHODS

A total of 1 45 endoscopic gastric biopsy specimens of AG, IM, and gastric dysplasia were studied. These molecular markers were localized by immunohistochemistry.

RESULTS

P53 was expressed in 15% of cases with gastric dysplasia and not in the pre-dysplastic stages of the gastric mucosa. All cases were concerning high-grade dysplasia. Cyclin D1 protein was almost undetectable in the precancerous lesions of gastric cancer. Cyclin D3 protein overexpression was seen in 10% of biopsies with IM, and 50% of biopsies with gastric dysplasia. High expression of p27(kip1) protein was demonstrated in all cases of chronic gastritis. As atrophy, IM, and dysplasia develop, expression of p27(kip1) protein is suppressed. In total, 15% of dysplastic cases showed no expression of p27(kip1) protein.

CONCLUSIONS

(i) P53 mutation must be a late event during the development of gastric cancer. (ii) Cyclin D1 protein overexpression may not play a role in the progression from normal to neoplastic gastric mucosa, while overexpression of cyclin D3 is an earlier event during gastric carcinogenesis, and its role must be further evaluated. (iii) Reduced expression of p27(kip1) is a rather early event in gastric tumorigenesis, before dysplastic changes occur.

HER-2/neu and p27Kip1 in progression of Fallopian tube carcinoma: an immunohistochemical and array comparative genomic hybridization study

AIMS

To determine expression of p53, HER-2/neu and p27(Kip1) in serous Fallopian tube carcinoma (FTC) in relation to stage and grade, and to investigate DNA copy number changes of HER-2 and P27KIP1 as a potential mechanism of altered expression status.

METHODS AND RESULTS

Immunohistochemistry was performed on 28 serous FTCs and 10 normal Fallopian tubes. p53 protein accumulated and p27(Kip1) was down-regulated significantly in early-stage FTCs compared with normal Fallopian tubes. HER-2/neu overexpression was absent in normal Fallopian tubes and in all stage I FTCs (n = 6) but present in 57% (12/21) of advanced-stage FTCs. No differences in expression between grade 2 and 3 tumours were detected. HER-2 gain/amplification was found by array comparative genomic hybridization in 23% (3/13) of analysed FTCs and all showed overexpression. HER-2/neu overexpression also occurred without DNA copy number changes in three other cases. For p27(Kip1), expression and DNA copy number were unrelated.

CONCLUSIONS

p53 accumulation and p27(Kip1) down-regulation seem to be early events in Fallopian tube carcinogenesis. HER-2/neu showed overexpression, caused by gain/amplification in 50%, and may be involved in progression of FTC. These data contribute to a better understanding of the molecular carcinogenesis of FTC and to possible new therapeutic approaches.

Expression and significances of P27 and Cyclin E protein in gastric carcinoma and precancerous lesion

AIM: To investigate the expression of P27 and Cyclin E protein in gastric carcinoma (GC) and precancerous lesion and their correlations with the clinicopathological parameters.

METHODS: Immunohistochemical staining was used to evaluate the expression of P27 and Cyclin E protein in the samples of normal gastric mucosa (NGM, n = 20), chronic superficial gastritis (CSG, n = 20), chronic atrophic gastritis (CAG) with metaplasia (n = 20), CAG with dysplasia (n = 20) and GC (n = 60), and their correlations with the clinicopathological parameters were analyzed.

RESULTS: The positive rates of P27 and Cyclin E protein expression were 100% and 5% in NGM, 85% and 10% in CSG, 70% and 20% in CAG with metaplasia, 45% and 30% in CAG with dysplasia, and 38.3%(23/60) and 40%(24/60) in GC, respectively. The positive rate of P27 expression in GC and CAG with dysplasia were lower than that in NGM, CSG, and CAG with metaplasia (P < 0.05), and the positive rate of Cyclin E expression in GC and CAG with dysplasia were higher than that in NGM, CSG, and CAG with metaplasia (P < 0.05). The expression of P27 and Cyclin E were significantly correlated with tumor differentiation, infiltration and clinical stages, and P27 expression was also correlated with lymph nodes metastasis. Furthermore, the expression of P27 was inversely correlated with Cyclin E expression in GC (r = -0.768, P < 0.05).

CONCLUSION: It is helpful to detect of P27 and Cyclin E protein expression in the judgment of GC progression, and combined analysis of them is of added prognostic value.

The prognostic significance of p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67 proteins expression in gastric cancer: a clinicopathological and immunohistochemical study of 121 Arab patients

BACKGROUND

The variability of prognosis within a pathological stage of gastric cancer (GC) at presentation, underscores the need for specific biological markers to identify subgroups of patients with aggressive course for intensive treatment. To our knowledge, this is the first study from an Arab population reporting on the relationship of p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67 expression, and clinicopathological features and their prognostic significance.

METHODS

Formalin-fixed paraffin-embedded tumors were studied by immunohistochemistry, using monoclonal antibodies to p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67. The results were correlated with clinicopathological features and survival.

RESULTS

M:F = 80:41; median age = 60 years; stage III and IV = 71%; and median follow-up = 34.4 months. Positive expression rates of p53, p27 kip1, p21 waf1, Ki67, and HER-2/neu were 54%, 40%, 8.3%, 70%, and 12% respectively. p53 expression correlated with age <60 years (P = 0.03), tumor size >5 cm (P = 0.01), p27 kip1 and Ki67 expression (P = 0.0001), and HER-2/neu (P = 0.04). p21 waf1 correlated inversely with T-stage (P = 0.008) and Her-2/neu expression correlated with histological grade (P = 0.04) and T-stage (P = 0.008). Univariate analysis showed that p53 overexpression (P = 0.01), fungating and infiltrative macroscopic appearance (P = 0.02), size >5 cm (P = 0.0001), lymph node metastasis (P = 0.0001), p T3 and T4 disease (P = 0.01), and overall stage III and IV (P = 0.0001) disease were adverse prognostic factors. Patients with tumor profiles p53 (-)/p27 (+) had better survival than those with p53 (+)/p27 kip1 (-)(P = 0.02). On multivariate analysis by Cox regression model, the expression of p53 (P = 0.03) and lymph node involvement (P = 0.01) were significant adverse prognostic factors for overall survival.

CONCLUSIONS

The expression of p53 in Arab patients with GC correlates with aggressive tumor characteristics and is an independent prognostic factor. The combined analysis of p53 and p27 kip1 is of added prognostic value.

Skp2 and p27kip1 expression in melanocytic nevi and melanoma: an inverse relationship

BACKGROUND

S-phase kinase associated protein-2 (Skp2) ubiquitin ligase p45(SKP2) is important in the degradation of p27kip1 (a cyclin dependent kinase inhibitor) and progression through the G1-S cell-cycle checkpoint. Low levels of p27 and high levels of Skp2 are related to poor prognosis in some cancers.

METHODS

Clinicopathologic features and immunohistochemical expression of Skp2 and p27kip1 were investigated in 198 melanocytic proliferations: 21 melanocytic nevi, 23 melanoma in situ, 119 primary melanoma, and 35 metastatic melanoma samples. Comparative and survival analyses were performed.

RESULTS

Progressive and significant increases and decreases in the nuclear expression of Skp2 and p27kip1, respectively, was identified moving from melanocytic nevi (0.05 +/- 0.2/85 +/- 15) to melanoma in situ (3 +/- 2/45 +/- 20) to primary cutaneous melanoma (12 +/- 9/30 +/- 25) to metastatic melanoma (25 +/- 15/15 +/- 20) (p < or = 0.006). Expression of these proteins also significantly correlated with increasing American Joint Committee on Cancer (AJCC) T (tumor) classification and AJCC stage (p < or = 0.01). Moreover, the level of these two proteins exhibited a significant inverse relationship (r = -0.4, p = 0.0001). Skp2 cytoplasmic labeling index of >20% predicted worse 10-year overall survival (38% vs. 86%, p = 0.04) in primary melanoma. Neither p27 nor Skp2 nuclear expression impacted significantly on prognosis.

CONCLUSIONS

Gain of Skp2 and loss of p27kip1 protein expression are implicated in melanoma progression where the level of p27kip1 may be regulated by targeted proteolysis via Skp2. Cytoplasmic expression of Skp2 defines a subset of aggressive melanomas and could represent another pathway of deregulation of the cell cycle.

Overexpression of cyclin D1 and interaction between p27Kip1 and tumour thickness predict lymph node metastases occurrence in lower lip squamous cell carcinoma

We have attempted to identify those subgroups of patients most likely to develop lymph node metastases from squamous cell carcinoma of the lower lip (LLSSC). A total of 97 subjects, who did not undergo elective neck dissection, were recruited into the 60-month disease-free survival study. After univariate analysis, tumour size, histological grading, maximal thickness, perineural invasion and immunoreactivity to cyclin D1 and p27Kip1 proteins proved to be significant factors. Tests of the effect of interaction between p27Kip1 LI and tumour thickness yielded that the impact of tumour thickness on the risk of lymph node metastases was modified by the percentage of p27Kip1 positive cells. Subsequent to models of multivariate analysis, tumour size, positive cyclin D1 protein expression, maximal thickness (> 5 mm), p27Kip1 LI (%) and the interaction term between p27Kip1 LI and tumour thickness retained strong independent predictive values for lymph node metastases. We suggest that immunohistochemistry for cyclin D1 and p27Kip1 may prove to be valuable ancillary tests for identifying LLSSC with metastatic potential.

p27 Protein and cancers of the gastrointestinal tract and liver: an overview

GOALS

The purpose of this review is to look at the evidence presented in the literature on the immunoexpression of p27 in cancers of the gastrointestinal tract and liver.

BACKGROUND

Cell cycle proteins have been shown to play an important role in the oncogenesis of many tumors. Several of these proteins have been examined in concert and in isolation, and some have been put forward as putative tumor markers. p27, which is an important inhibitory protein in the cell cycle and belonging to a group of cyclin-dependent kinase inhibitors, has also been studied in several malignancies, most notably breast, lung, bladder, and prostate cancers. Considerable work has also been done on the expression of this protein in cancers occurring within the gastrointestinal tract.

RESULTS

Cancers occurring in the major sites of the gastrointestinal tract (esophagus, stomach, and colorectum) and liver show a similar pattern with regard to p27 protein levels. p27 emerges as a statistically significant predictor of survival and tumor behavior. It has been suggested that p27 loss occurs early in the carcinogenesis process, with dysplastic epithelium having decreased expression. The more aggressive, metastasizing cancers tend to lack p27 expression as well. Some studies have also invoked the subcellular localization of p27 (cytoplasmic versus nuclear) as also being of prognostic value.

CONCLUSION

Therefore, in gastrointestinal and hepatic cancers, low p27 expression is regarded as an important adverse prognostic factor.

p27(Kip1) (Cdkn1b)-deficient mice are susceptible to chemical carcinogenesis and may be a useful model for carcinogen screening

The two-year rodent bioassay is one of several tests that are widely used by governmental regulatory agencies as well as pharmaceutical and chemical companies to determine the carcinogenic potential of chemicals or environmental agents where human exposure is anticipated. That this assay has remained relatively unchanged for the last 25 years is a testament to the power of this approach to identify carcinogens and thus to minimize human exposure. However, there has long been controversy over the specificity and relevance of the rodent bioassay as well as its high cost in terms of time, expense, and numbers of mice. Much discussion has been generated in recent years over how to improve the 2-year rodent bioassay for more accurate and faster detection of potential human carcinogens. Here, we argue that the use of p27(Kip1) (Cdkn1b) knockout mouse for carcinogen screening may solve several shortcomings inherent in the conventional bioassay while preserving its best quality, that is, protecting public health by providing reliable in vivo information on the potential of chemicals to cause cancer.

p27 Kip1 expression is reduced in pancreatic carcinoma but has limited prognostic value

p27(Kip1) is a cyclin-dependent kinase inhibitor whose loss in malignant tumors is associated with disease progression and an unfavorable clinical outcome. There is limited information about its expression in pancreatic carcinomas. In a previous Japanese study, p27(Kip1) loss was a powerful negative prognostic factor. In the present study, we assessed the expression of p27(Kip1) in resected pancreatic ductal adenocarcinomas from 46 European patients and in associated lymph node metastases from 13 patients, using a standard avidin-biotin peroxidase complex immunohistochemical method. We also analyzed the relationships among p27(Kip1) expression, pathologic features, and clinical outcome. The extent of p27(Kip1) expression (ie, the percentage of cells expressing p27(Kip1)) was lower in carcinomas than in nonneoplastic ductal epithelia. Carcinomas with <5% p27(Kip1) expression were more likely to be poorly or moderately differentiated than well differentiated (P =.022). p27(Kip1) expression did not correlate with patient gender, tumor maximum dimension, T classification, lymph node metastasis, or International Union Against Cancer stage. No significant difference was seen between the extent of p27(Kip1) expression in lymph node metastases and their corresponding primary tumors. Univariate survival analysis showed that an increased risk of death was associated with 2 established prognostic factors: tumor size >5 cm (P =.011) and incomplete surgical excision (P =.016). Trends toward worse survival for patients whose primary tumors had <4% p27(Kip1) expression (P =.060) and for patients whose lymph node metastases had <5% p27(Kip1) expression (P =.054) were seen, but multivariate analysis suggested that p27(Kip1) expression was not independently prognostic. The findings raise the possibility that abnormalities of p27(Kip1) play a role in the pathogenesis of pancreatic ductal adenocarcinoma. However, the extent of p27(Kip1) expression in lymph node metastases and primary tumors is similar. Also, reduced p27(Kip1) expression has limited prognostic value, at least in European patients.

Low level of p27(Kip1) protein expression in gastric adenocarcinoma is associated with disease progression and poor outcome

BACKGROUND AND OBJECTIVES

Low tumor expression of the p27(Kip1) protein, which is involved in cell cycle control and apoptosis, is considered a negative prognostic factor in different types of cancer. The aim of this study was to evaluate the clinical and pathological significance of low p27(Kip1) protein expression in patients who had undergone resection for gastric adenocarcinoma.

METHODS

p27(Kip1) protein was studied by immunohistochemistry in formalin-fixed tumor sections from 95 patients who underwent resection for gastric adenocarcinoma between 1991 and 1996. Based on the median value of protein expression, p27(Kip1) protein expression was classified as low or high.

RESULTS

Low p27(Kip1) protein expression was significantly associated with tumor de-differentiation, increased penetration through the gastric wall, lymph node metastasis, and advanced tumor stage. In the group of 84 patients who underwent curative surgery, 5-year survival was 74% in cases with high p27(Kip1) protein expression and 38% in those with low p27(Kip1) protein expression (P < 0.001). At multivariate analysis, low p27(Kip1) protein expression was an independent negative prognostic factor for survival (RR = 3.671; P = 0.004).

CONCLUSIONS

In gastric adenocarcinoma, low p27(Kip1) protein expression is associated with poorly differentiated and advanced tumors and is a negative prognostic factor of potential clinical value.

Cyclin A correlates with carcinogenesis and metastasis, and p27(kip1) correlates with lymphatic invasion, in colorectal neoplasms

Cyclin A binds to CDK2 and plays critical roles when cells proliferate; staining for Ki67 can monitor the proliferation. The cyclin A expression pattern remains unclear in colorectal carcinogenesis and remote metastasis, however, and no one has reported on the association of its expression with key clinicopathologic factors in primary cancer. p27(kip1) protein-an extremely important inhibitor of CDK2-seems unchanged as colorectal cancers metastasize to the lymph nodes, a result contrary to that seen in gastric and prostatic cancers. To clarify the role of cyclin A in multistage colorectal neoplasms, cyclin A, CDK2, and Ki67 were immunohistochemically stained in 22 normal mucosa, 9 hyperplastic polyps, 61 adenomas, 197 primary carcinomas, 21 lymph node metastases, and 10 hepatic metastases. To clarify the alteration of p27(kip1) during lymphatic invasion, p27(kip1) was also stained in 21 primary cancers and paired lymph node foci. Situated in nuclei, cyclin A expression gradually increased from mild through moderate to severe dysplasia in adenomas and from normal tissue through hyperplasia to adenoma to early carcinoma. Expression was significantly decreased in the hepatic metastases and in the primary cancers showing venous invasion, deep infiltration, lymph node metastasis, mucinous type, advanced stage, or short postoperative survival time. Elevated cyclin A not only was linked with elevated CDK2 in primary cancers, but also was associated with increased Ki67 in both adenomas and primary carcinomas. Lymph node metastases lost more p27(kip1) than primary foci and hepatic lesions. Thus, dysregulation of cyclin A and its control mechanisms may contribute to colorectal carcinogenesis; abatement of overexpression of cyclin A is associated with hepatic metastasis and cancerous invasion. Loss of p27(kip1) may promote lymph node metastasis.

Pathway-specific tumor suppression. Reduction of p27 accelerates gastrointestinal tumorigenesis in Apc mutant mice, but not in Smad3 mutant mice

Expression of the cyclin-dependent kinase inhibitor p27(Kip1) (p27) is frequently reduced in human colorectal cancer, and this correlates with poor patient prognosis. To clarify the role of p27 in gastrointestinal (GI) cancer, we measured p27 expression, as well as the effect of germline deletion of p27, in 3 different mouse models of GI neoplasia. p27 expression was frequently reduced in GI tumors arising in 1,2-dimethylhydrazine (DMH) treated mice, and in Apc mutant Min/+ mice, but not in GI tumors arising in Smad3 mutant mice. Germline deletion of p27 resulted in accelerated tumor development and increased tumor cell proliferation in both DMH treated and Min/+ mice, but not in Smad3 mutant mice. p27 deficiency also led to increased adenoma to adenocarcinoma progression. These results indicate that reduction of p27 cooperates with mutations in Apc but not in Smad3 during GI tumorigenesis. Thus, tumor suppression by p27 is contingent on the specific oncogenic pathway that drives tumor development.

Overexpression of cyclin D1 and underexpression of p27 predict lymph node metastases in papillary thyroid carcinoma

Lymph node metastasis in papillary thyroid carcinoma increases the morbidity of treatment and the risk of local regional relapse and may also affect cure rates and survival. Factors that predict lymph node metastasis are, however, unclear. We analyzed 125 patients with papillary thyroid carcinoma for factors that predict lymph node metastasis. On univariate analysis, age, extrathyroidal extension, tumor focality, overexpression of cyclin D1, and underexpression of p27 predicted lymph node metastasis, whereas patient gender and tumor size did not. On multivariate analysis, extrathyroidal extension, overexpression of cyclin D1, and underexpression of p27 proved to be strong independent predictors of lymph node metastasis. We suggest that immunohistochemistry for cyclin D1 and p27 will prove valuable in identifying papillary thyroid carcinomas with metastatic potential.

P27Kip1 expression and survival in NO gastric carcinoma

p27Kip1, a cyclin-dependent kinase inhibitor, is considered to be a tumor suppressor gene. Absent or reduced expression of the p27Kip1 protein has been reported being a negative prognostic marker in primary lung, breast, colon, bladder, and prostate carcinomas. p27Kip1 protein expression was evaluated in a series of 96 gastric carcinomas with no lymph node involvement (NO) to verify any impact on the clinical outcome. The analysis also considered the classic clinico-pathological parameters, such as age, sex, and depth of tumor invasion (pT). The most widely used classification systems for gastric carcinoma were adopted. The expression of p27pKip1 was related neither to the pT category nor to tumor histology. Kaplan-Meier analysis documented a significant impact of an advanced pT category (p < 0.0001) and p27Kip1-reduced expression (p < 0.0002) on survival. Multivariate analysis confirmed that the reduced p27Kip1 protein expression was a strong independent predictor of poor outcome, ranking second to the pT category only (p < 0.006 and p < 0.004 respectively). As reported for other neoplasms, the expression of p27Kip1 appears to be associated with the clinical outcome of gastric carcinoma.

Quercetin inhibits the invasion and mobility of murine melanoma B16-BL6 cells through inducing apoptosis via decreasing Bcl-2 expression

Quercetin has been known to have anti-tumor and anti-oxidation activities. In the present study, we have investigated its in vitro anti-metastatic activity. Quercetin inhibited the invasion and mobility of murine melanoma B16-BL6 cells in a dose-dependent manner but did not affect their adhesion to either laminin, fibronectin, or type VI collagen. Moreover, quercetin significantly inhibited the proliferation of B16-BL6 cells only in the case of time incubation longer than 48 h. Quercetin dose-dependently decreased the cell rates in S and G2-M phases of cell cycle. The effect of quercetin to cause a remarkable apoptosis of B16-BL6 cells was also demonstrated by flow cytometric assay as well as DNA fragmentation with a typical 180-bp ladder band in agarose electrophoresis and a quantitative analysis. Furthermore, quercetin markedly inhibited the expression of anti-apoptotic protein Bcl-2 but hardly influenced Bcl-XL. These results suggest that the inhibition of quercetin on invasiveness and migration of B16-BL6 cells are closely associated with the arrest of cell cycle as well as the induction of apoptosis by decreasing the Bcl-2 expression.

Analysis of early (pT1) gastric cancer with submucosal invasion: surgical management and possibility to schedule less invasive surgery

BACKGROUND

Early gastric cancer (EGC) is one of the popular targets of less invasive surgery. The aim of the present study is to clarify the possibility of scheduling a less invasive surgery for EGC cases with submucosal (SM) invasion.

METHODS

Eighty cases of EGC with SM invasion were analyzed clinicopathologically and immunohistochemically. Correlations between factors that reflect cancer progression and data from endoscopic examination were investigated.

RESULTS

Thirteen cases (16.3%) showed lymph node metastasis and the numbers of metastasis-positive lymph nodes ranged from 1 to 18. Two cases showed lymph node metastasis not only in the perigastric area, but also along the left gastric artery and the common hepatic artery. Only the tumor size showed a significant correlation with lymph node metastasis (P = .014) using the data from preoperative endoscopic examination. With respect to p53 overexpression, there was no significant correlation with pathologic factors in EGC with SM invasion. The simple protuberance types that were <2 cm in diameter had no lymph node metastasis.

CONCLUSIONS

It seems difficult to predict the progression of EGC with SM invasion from the data currently obtained by preoperative endoscopic examination. It was suggested that less invasive surgery could be scheduled only for simple protuberance type cases that were <2 cm in diameter. Radical gastrectomy and D2 lymph node dissection is required, in open surgery or laparoscopic surgery, for any other type of EGC with SM invasion.

p27 immunostaining is related to prognosis in malignant mesothelioma

AIMS

To evaluate the prognostic value of the proliferation-associated antigen p27 in malignant mesothelioma.

METHODS AND RESULTS

Sections from 36 patients with malignant mesothelioma were immunohistochemically stained for the p27 antigen. The results were quantified by recording the proportion of positively stained nuclei and these data were tested for association with patient survival. p27 expression was also compared with tumour type, MIB-1 expression, apoptotic and mitotic indices. Patients with pleural malignant mesothelioma showing low p27 expression (< 53% of cells positive) survived for significantly shorter periods of time than those with high p27 expression (> or = 53% of cells positive) (P=0.04). The 50% survival time of subjects with low p27 was 4-6 months whereas for those with high p27 expression it was 10-11 months. There was no significant association between p27 expression and MIB-1, apoptotic or mitotic indices.

CONCLUSIONS

Low p27 expression in pleural malignant mesothelioma is associated with a significantly worse prognosis. p27 appears to be an independent prognostic variable which may be of value in counselling patients with malignant mesothelioma.