Low tumour cell proliferation at the invasive margin is associated with a poor prognosis in Dukes' stage B colorectal cancers

PP2A B55α inhibits epithelial-mesenchymal transition via regulation of Slug expression in non-small cell lung cancer

PP2A B55α, encoded by PPP2R2A, acts as a regulatory subunit of the serine/threonine phosphatase PP2A. Despite a frequent loss of heterozygosity of PPP2R2A in cases of non-small cell lung cancer (NSCLC), research on PP2A B55α's functions remains limited and controversial. To investigate the biological roles of PP2A B55α, we conducted bulk RNA-sequencing to assess the impact of PPP2R2A knockdown using two shRNAs in a NSCLC cell line. Gene set enrichment analysis (GSEA) of the RNA-sequencing data revealed significant enrichment of the epithelial-mesenchymal transition (EMT) pathway, with SNAI2 (the gene encoding Slug) emerging as one of the top candidates. Our findings demonstrate that PP2A B55α suppresses EMT, as PPP2R2A deficiency through knockdown or homozygous or hemizygous depletion promotes EMT and metastatic behavior in NSCLC cells, as evidenced by changes in EMT biomarkers, invasion and migration abilities, as well as metastasis in a tail vein assay. Mechanistically, PP2A B55α inhibits EMT by downregulating SNAI2 expression via the GSK3β-β-catenin pathway. Importantly, PPP2R2A deficiency also slows cell proliferation by disrupting DNA replication, particularly in PPP2R2A-/- cells. Furthermore, PPP2R2A deficiency, especially PPP2R2A-/- cells, leads to an increase in the cancer stem cell population, which correlates with enhanced resistance to chemotherapy. Overall, the decrease in PP2A B55α levels due to hemizygous/homozygous depletion heightens EMT and the metastatic or stemness/drug resistance potential of NSCLC cells despite their proliferation disadvantage. Our study highlights the significance of PP2A B55α in EMT and metastasis and suggests that targeting EMT/stemness could be a potential therapeutic strategy for treating PPP2R2A-deficient NSCLC.

Characterisation of colorectal cancer by hierarchical clustering analyses for five stroma-related markers

Evidence for the tumour-supporting capacities of the tumour stroma has accumulated rapidly in colorectal cancer (CRC). Tumour stroma is composed of heterogeneous cells and components including cancer-associated fibroblasts (CAFs), small vessels, immune cells, and extracellular matrix proteins. The present study examined the characteristics of CAFs and collagen, major components of cancer stroma, by immunohistochemistry and Sirius red staining. The expression status of five independent CAF-related or stromal markers, decorin (DCN), fibroblast activation protein (FAP), podoplanin (PDPN), alpha-smooth muscle actin (ACTA2), and collagen, and their association with clinicopathological features and clinical outcomes were analysed. Patients with DCN-high tumours had a significantly worse 5-year survival rate (57.3% versus 79.0%; p = 0.044). Furthermore, hierarchical clustering analyses for these five markers identified three groups that showed specific characteristics: a solid group (cancer cell-rich, DCNLowPDPNLow); a PDPN-dominant group (DCNMidPDPNHigh); and a DCN-dominant group (DCNHighPDPNLow), with a significant association with patient survival (p = 0.0085). Cox proportional hazards model identified the PDPN-dominant group (hazard ratio = 0.50, 95% CI = 0.26-0.96, p = 0.037) as a potential favourable factor compared with the DCN-dominant group. Of note, DCN-dominant tumours showed the most advanced pT stage and contained the lowest number of CD8+ and FOXP3+ immune cells. This study has revealed that immunohistochemistry and special staining of five stromal factors with hierarchical clustering analyses could be used for the prognostication of patients with CRC. Cancer stroma-targeting therapies may be candidate treatments for patients with CRC.

Prognostic Biomarkers of Cell Proliferation in Colorectal Cancer (CRC): From Immunohistochemistry to Molecular Biology Techniques

Colorectal cancer (CRC) is one of the most common and severe malignancies worldwide. Recent advances in diagnostic methods allow for more accurate identification and detection of several molecular biomarkers associated with this cancer. Nonetheless, non-invasive and effective prognostic and predictive testing in CRC patients remains challenging. Classical prognostic genetic markers comprise mutations in several genes (e.g., APC, KRAS/BRAF, TGF-β, and TP53). Furthermore, CIN and MSI serve as chromosomal markers, while epigenetic markers include CIMP and many other candidates such as SERP, p14, p16, LINE-1, and RASSF1A. The number of proliferation-related long non-coding RNAs (e.g., SNHG1, SNHG6, MALAT-1, CRNDE) and microRNAs (e.g., miR-20a, miR-21, miR-143, miR-145, miR-181a/b) that could serve as potential CRC markers has also steadily increased in recent years. Among the immunohistochemical (IHC) proliferative markers, the prognostic value regarding the patients' overall survival (OS) or disease-free survival (DFS) has been confirmed for thymidylate synthase (TS), cyclin B1, cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki-67. In most cases, the overexpression of these markers in tissues was related to worse OS and DFS. However, slowly proliferating cells should also be considered in CRC therapy (especially radiotherapy) as they could represent a reservoir from which cells are recruited to replenish the rapidly proliferating population in response to cell-damaging factors. Considering the above, the aim of this article is to review the most common proliferative markers assessed using various methods including IHC and selected molecular biology techniques (e.g., qRT-PCR, in situ hybridization, RNA/DNA sequencing, next-generation sequencing) as prognostic and predictive markers in CRC.

Crude extract of Jatobá leaves promotes canine osteosarcoma cell D17 proliferation

Background and Aim

New substances for neoplasm treatment have to be carefully studied to minimize adverse effects and prevent disease progression stimulation. Jatobá is a typical tree of the Cerrado and Caatinga biome, with antifungal, antimicrobial, larvicide, antioxidant, and antiproliferative properties. This study aimed to investigate the action of the crude extract of Jatobá leaves (EBFJ) on canine osteosarcoma (CO) cells and analyze the expression of biomarkers in neoplasm progression.

Materials and Methods

D17 cells were cultured and subjected to treatment with EBFJ at different concentrations (10 μg/mL; 100 μg/mL; 1000 μg/mL; 2000 μg/mL; and 5000 μg/mL) and exposure times (24 h, 48 h, and 72 h). The tetrazolium reduction assay and the immunocytochemistry technique, with anti-Bcl2, anti-p53, and anti-Ki-67 antibodies, were used to observe the effect of the extract on cell proliferation.

Results

Doses of 2000 µg and 5000 µg had cell viability of 300.80% and 361.84%, respectively. The extract did not show significant cytotoxicity of samples with the control group. The confluence of cells, the number of labeled cells, and the expression of Bcl2, Ki-67, and p53 were higher in the groups treated with EBFJ, with a statistical difference from the group without treatment.

Conclusion

EBFJ was not cytotoxic and had a proliferative effect on CO D17 cells. The confluence of cells, the number of labeled cells, and the expression of Bcl2, Ki-67, and p53 were higher in the groups treated with the extract.

SPATA18 Expression Predicts Favorable Clinical Outcome in Colorectal Cancer

Dysregulation of mitochondrial quality control has been reported to be associated with cancer and degenerative diseases. SPATA18 (spermatogenesis-associated 18, also known as Mieap) encodes a p53-inducible protein that can induce lysosome-like organelles within mitochondria that eliminate oxidized mitochondrial proteins and has tumor suppressor functions in mitochondrial quality control. In the present study, 268 primary colorectal cancers (CRCs) were evaluated immunohistochemically for SPATA18 expression to assess its predictive utility and its association with cellular proliferation activity. Furthermore, the association with p53 immunoreactivity, a surrogate marker for TP53 mutation, was analyzed. Non-neoplastic colonic mucosa showed cytoplasmic SPATA18 expression. Seventy-two percent of the lesions (193/268) displayed high SPATA18 expression in the cytoplasm of CRC cells. Univariate analyses revealed significant associations between SPATA18 expression and tumor size (p < 0.0001), histological differentiation (p = 0.0017), and lymph node metastasis (p = 0.00039). The log-rank test revealed that patients with SPATA18-high CRCs had significantly better survival than SPATA18-low patients (p < 0.0001). Multivariate Cox hazards regression analysis identified tubular-forming histology (hazard ratio [HR] = 0.25), age < 70 years (HR = 0.50), and SPATA18-high (HR = 0.55) as potential favorable factors. Lymph node metastasis (HR = 1.98) and peritoneal metastasis (HR = 5.45) were cited as potential independent risk factors. Cellular proliferation activity was significantly higher in SPATA18-high tumors. However, no significant correlation was detected between SPATA18 expression and p53 immunoreactivity or KRAS/BRAF mutation status. On the basis of our observations, SPATA18 immunohistochemistry can be used in the prognostication of CRC patients.

PBK expression predicts favorable survival in colorectal cancer patients

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers worldwide with high morbidity and mortality rates. The discovery of small molecule anticancer reagents has significantly affected cancer therapy. However, the anticancer effects of these therapies are not sufficient to completely cure CRC. PDZ-binding kinase (PBK) was initially identified as a mitotic kinase for mitogen-activated protein kinase and is involved in cytokinesis and spermatogenesis. Aberrant expression of PBK has been reported to be closely associated with malignant phenotypes of many cancers and/or patient survival. However, the expression of PBK and its association to patient survival in CRC have not been fully elucidated. In the present study, 269 primary CRCs were evaluated immunohistochemically for PBK expression to assess its ability as a prognostic factor. CRC tumor cells variably expressed PBK (range, 0-100%; median, 32%) in the nucleus and cytoplasm. Univariate analyses identified a significant inverse correlation between PBK expression and pT stage (P<0.0001). Furthermore, patients carrying CRC with higher PBK expression showed significantly favorable survival (P=0.0094). Multivariate Cox proportional hazards regression analysis revealed high PBK expression (HR, 0.52; P=0.015) as one of the potential favorable factors for CRC patients. PBK expression showed significant correlation to Ki-67 labeling indices (ρ=0.488, P<0.0001). In vitro, the PBK inhibitor OTS514 suppressed cellular proliferation of CRC cells with PBK expression through downregulation of P-ERK and induction of apoptosis. These results suggest that PBK-targeting therapeutics may be useful for the treatment of PBK-expressing CRC patients.

High phospho-histone H3 expression uniquely predicts favorable survival among four markers of cellular proliferation in colorectal cancer

Colorectal cancer (CRC) is one of the most frequent gastrointestinal cancers worldwide, with high morbidity and mortality rates. Despite numerous attempts to identify prognostic markers for the CRC patients, the significance of the association of cellular proliferation markers with survival is controversial. Here we used immunohistochemistry to detect four markers of cellular proliferation expressed in primary CRC tissue specimens (n = 269) to assess their potential to serve as prognostic factors. CRC cells variably expressed phospho-histone H3 (PHH3) (range, 0-76 per high-powered field (HPF); median, 7 per HPF), cyclin A (CCNA) (range, 11.3-73.7%; median, 32%), geminin (GMNN) (range, 7.8-82.0%; median, 37.1%), and marker of proliferation Ki-67 (MKI67) (range, 4.9-96.6%; median, 49.6%). Among them, patients with PHH3-high (≥7 per HPF) tumors uniquely experienced significantly longer 5-year survival than those with PHH3-low (≤6 per HPF) (81.8% vs. 65.5%; P = 0.0047). Multivariable Cox hazards regression analysis identified PHH3-high (hazard ratio, 0.54; 95% confidence interval, 0.31-0.92; P = 0.025) as potential favorable factors. PHH3 levels inversely associated with pT stage (P < 0.0001) and were significantly and inversely associated with tumor diameter (ρ = -0.314, P < 0.0001). These findings support the use of PHH3 immunohistochemistry for predicting the prognoses of patients with CRC.

Long-term model of colitis-associated colorectal cancer suggests tumor spread mechanism and nature of cancer stem cells

Although chemical-induced animal models of colorectal cancer (CRC) suggest a lot about the disease, more efforts are required to establish metastasis models. Azoxymethane (AOM) and dextran sodium sulfate (DSS)-treated (AOM/DSS) Crl:CD-1 mice were sacrificed after 10 or 20 weeks in our previous study, and most colon tumors exhibited intramucosal adenocarcinomas. Our observations were extended until 30 weeks to study a colitis-associated advanced CRC mouse model, and explore whether linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr) immunostaining-positive cells were involved in the progressive course of colitis-associated CRC as cancer stem cells. AOM/DSS mice were sacrificed at 10, 20 and 30 weeks after AOM administration. Following the histopathological analysis, immunohistochemical staining was performed for the following markers: CD34, podoplanin, β-catenin, E-cadherin, Ki67, Bmi1 and pSmad2/3L-Thr. Compared with AOM/DSS mice at 10 and 20 weeks, submucosal tumor infiltration and tumor invasion into vessels were markedly increased at 30 weeks. In the parts of colon tumors from AOM/DSS mice, particularly in mice at 30 weeks, the positive signal of E-cadherin was clearly reduced in the cell membranes. The percentage of Ki67-positive tumor cells in mucosal areas of AOM/DSS mice was higher than that in the sites of submucosal infiltration. In mucosal areas of colon tumors, pSmad2/3L-Thr-positive cells were scattered among tumor cells. At sites of submucosal infiltration and vessel invasion of these tumors, pSmad2/3L-Thr-positive cells were also observed among tumor cells. In colon tumors from AOM/DSS mice at 30 weeks, the percentage of pSmad2/3L-Thr-positive cells among the nuclear β-catenin-positive tumor cells was higher than that among the cytoplasmic β-catenin-positive tumor cells. For both non-neoplastic and neoplastic epithelial cells, pSmad2/3L-Thr-positive cells exhibited immunohistochemical co-localization with Bmi1. The present study developed an advanced CRC mouse model that exhibited tumor infiltration into the submucosa and invasion into vessels. The present study re-confirmed the theory that pSmad2/3L-Thr-positive cells may be cancer stem cells.

Loss of enhancer of zeste homologue 2 (EZH2) at tumor invasion front is correlated with higher aggressiveness in colorectal cancer cells

PURPOSE

Enhancer of zeste homolog 2 (EZH2) is associated with epigenetic gene silencing and aggressiveness in many tumor types. However, the prognostic impact of high EZH2 expression is controversially discussed for colorectal cancer. For this reason, we immunohistochemically analyzed EZH2 expression in 105 specimens from colon cancer patients separately for tumor center and invasion front.

METHODS

All sections from tissue microarrays were evaluated manually and digitally using Definiens Tissue Studio software (TSS). To mirror-image the EZH2 status at the tumor invasion front, we treated HCT116 colon cancer cells with the EZH2 inhibitor 3-Deazaneplanocin A (DZNep) and studied the growth of in ovo xenografts in the chorioallantoic membrane (CAM) assay.

RESULTS

We showed a significant decrease in EZH2 expression and the repressive H3K27me3 code at the tumor invasion front as supported by the TSS-constructed heatmaps. Loss of EZH2 at tumor invasion front, but not in tumor center was correlated with unfavorable prognosis and more advanced tumor stages. The observed cell cycle arrest in vitro and in vivo was associated with higher tumor aggressiveness. Xenografts formed by DZNep-treated HCT116 cells showed loosely packed tumor masses, infiltrative growth into the CAM, and high vessel density.

CONCLUSION

The differences in EZH2 expression between tumor center and invasion front as well as different scoring and cutoff values can most likely explain controversial literature data concerning the prognostic value of EZH2. Epigenetic therapies using EZH2 inhibitors have to be carefully evaluated for each specific tumor type, since alterations in cell differentiation might lead to unfavorable results.

Reprogramming of CaCo2 colorectal cancer cells after using the complex of poly-(N-vinylpyrrolidone) with small non-coding RNAs

Small non-coding RNAs control normal development and differentiation in the embryo. These regulatory molecules play a key role in the development of human diseases and are used often today for researching new treatments for different pathologies. In this study, CaCo2 colorectal adenocarcinoma cells were initially epigenetically reprogrammed and transformed into CD4+ cells with nano-sized complexes of amphiphilic poly-(N-vinylpyrrolidone) (PVP) with miRNA-152 and piRNA-30074. The transformation of cells was confirmed by morphological and genetic changes in the dynamic of reprogramming. CD4+ lymphocytes marker was detected using immunofluorescence. Amphiphilic poly-(N-vinylpyrrolidone)/small non-coding RNAs complexes were investigated for transfection efficiency and duration of transfection of CaCo2 colorectal adenocarcinoma cells using fluorescence.

Ki-67 Prognostic Value in Different Histological Grades of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Introduction:

Abnormal cell proliferation appears to be a possible predictor of tumorigenesis, Ki-67 protein expression is closely related to the cell proliferation and could be used as a biomarker for the growth in the most of human tumors. The aim of the study: Investigating of Ki-67 expression in the pathological grades of oral epithelial dysplasia and oral squamous cell carcinomas.

Materials and Methods:

The sample consisted of 30 formalin-fixed, paraffin-embedded specimens of oral epithelial dysplasia (OED), 30 other of oral squamous cell carcinomas (OSCC), and 10 normal oral epithelium (NOE) were conventionally stained with hematoxylin and eosin and immunohistochemically stained with Ki-67 monoclonal antibody.

Results:

Expression of Ki-67 was restricted to the basal layers in the normal oral epithelium whereas Ki-67 positive cells in oral epithelial dysplasia (OED) were located in the basal, suprabasal and spinous layers, Ki-67 expression was increased in high-risk cases. Ki-67 positive cells in well-differentiated (OSCC) were located mainly in the periphery of the tumor nests, in moderately-differentiated (OSCC) were located in both peripheral and part of a center of the tumor nests whereas it was diffused in most of the Poorly-differentiated (OSCC). Statistical analysis indicated a significant difference between the expression in (OED) and (NOE), (OSCC) and (NOE), and no differences between (OED) and (OSCC).

Conclusion:

This study has concluded that Ki-67 antigen could be used as a marker for the histological grading of OED and OSCC, Expression of Ki 67 increased according to the severity of oral epithelial dysplasia.

Higher Ki67 expression in fibroblast like cells at invasive front indicates better clinical outcomes in oral squamous cell carcinoma patients

Background: Ki67 has been a key role for the treatment options and prognosis evaluation in some kinds of tumors; however, the spatial expression of Ki67 in oral squamous cell carcinoma (OSCC) has not been fully-evaluated. Therefore, in the present study, we aimed to elucidate the prognosis value of Ki67 spatial expression including in different cell types and at different compartments of tumor in OSCC patients. Methods: Immunohistochemical expression of Ki67 in tumor cells (TCs) and fibroblast like cells (FLCs) at center of tumor (CT) and invasive front (IF) was evaluated in 109 OSCC patients. Then correlations of Ki67 expressions with clinicopathological parameters were analyzed by Chi-square test, and survival curves were evaluated by Kaplan-Meier methods. Furthermore, univariate and multivariate analysis were performed to assess the diagnostic values of Ki67 expression by the Cox regression model. Results: Ki67 expression in TCs was much higher than in FLCs both at CT and IF compartments, but Ki67 expression in TCs was simultaneously higher at CT than that at IF (P=0.0004), which was converse to Ki67 expression in FLCs (P<0.0001). Additionally, high Ki67 expression in FLCs at IF was significantly associated with poor tumor differentiation (P=0.003), worse depth of invasion (DOI, P=0.027) and worst pattern of invasion (WPOI, P=0.041), but Ki67 expression in TCs had no correlation with clinical parameters no matter at CT or IF. Moreover, patients with higher Ki67 expression in TCs at CT had significantly increased risk for OS (overall survival; HR:1.935, 95% CI: 1.181-4.823, P=0.0395) and DFS (disease-free survival; HR: 2.974, 95% CI:1.189-5.023, P=0.046). On contrary, higher Ki67 expression in FLCs at IF was correlated with better OS (HR: 0.15, 95% CI: 0.018-0.846, P=0.0396) and DFS (HR: 0.15, 95% CI: 0.018-0.947, P=0.0445). Whereas, Ki67 expression both at TCs in IF and at FLCs in CT had no significant prognostic value for OS and DFS. Furthermore, Cox multivariate analysis revealed that Ki67 expression in FLCs at IF could not be an independent prognostic factor for OSCC patients. Conclusion: These results show that higher Ki67 expression in FLCs at IF indicated better clinical outcomes for OSCC patients.

Difference between right and left colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors around the world. The incidence of CRC has increasing, but the prognosis is quite different. In recent years, the impact of tumor site on the treatment and prognosis of CRC has attracted widespread attention, and the research for differences between tumors provides a theoretical basis for precise treatment. This review aims to summarize the difference between right and left CRC.

Plk2 Loss Commonly Occurs in Colorectal Carcinomas but not Adenomas: Relationship to mTOR Signaling

Plk2 is a target of p53. Our previous studies demonstrated that with wild-type p53, Plk2 impacts mTOR signaling in the same manner as TSC1, and Plk2-deficient tumors grew larger than control. Other investigators have demonstrated that Plk2 phosphorylates mutant p53 in a positive feedback loop. We investigated Plk2’s tumor suppressor functions in relationship to mTOR signaling. Archival specimens from 12 colorectal adenocarcinomas were stained for markers including Plk2, phosphorylated mTOR (serine 2448) and ribosomal S6 (Serine 235/236). We show that Plk2 is expressed in normal colon, with a punctate staining pattern in supranuclear cytoplasm. In colorectal adenocarcinoma, Plk2 demonstrates complete or partial loss of expression. Strong expression of phosphorylated mTOR is observed in the invasive front. Phosphorylated S6 expression partially correlates with phosphorylated mTOR expression but appears more diffuse in some cases. p53 and Ki67 expression is diffuse, in the subset of cases examined. In order to determine whether Plk2 is lost prior to the development of invasive cancer, 8 colon polyps from 6 patients were evaluated for Plk2 expression. All polyps are positive for Plk2. A Cancer Genome Atlas search identified Plk2 mutations to be infrequent in colorectal adenocarcinomas. Neither Plk2 methylation (in the gene body) nor copy number variations correlated with changes in mRNA expression levels. Loss of Plk2 expression along with accentuated expression of phosphorylated mTOR and phosphorylated S6 at the invasive front in some colorectal carcinomas is consistent with previous findings that an interaction between Plk2 and TSC1 / mTOR signaling molecules plays a role in tumor suppression. Plk2 protein expression is lost at the same stage in colorectal carcinogenesis as p53. The p53 dependence of Plk2 loss and tumor suppressor function in relationship to mTOR signaling may have therapeutic implications.

Clinical Significance of Preoperative Serum Sialic Acid Levels in Colorectal Cancer: Utility in the Detection of Patients at High Risk of Tumor Recurrence

This study was conducted to evaluate the significance of preoperative serum sialic acid levels in the diagnosis and prognosis of colorectal cancer (CRC). Total sialic acid (TSA) was determined by the thiobarbituric acid method and normalized to total protein (TP). A postoperative follow-up of CRC patients classified as Dukes’ stages A, B or C was performed and survival analysis was carried out to evaluate the impact of sialic acid levels on tumor recurrence. Our diagnostic studies indicate that TSA/TP is a better marker than either TSA or carcinoembryonic antigen (CEA), especially for the detection of CRC patients at an early stage. At a cutoff of 30.90 nmol/mg of protein, TSA/TP showed a sensitivity of 85% with a specificity of 97% to discriminate CRC patients from healthy donors. In survival analysis, both TSA and TSA/TP were found to be significant prognostic factors for tumor recurrence in CRC. Furthermore, TSA/TP could distinguish patients at high risk of recurrence within Dukes’ stage B and in multivariate analysis it was identified as the best independent prognostic factor. According to our results, preoperative serum TSA/TP content could supply additional information to that provided by Dukes’ stage about the prognosis of CRC patients.

Classification of gene signatures for their information value and functional redundancy

Gene signatures are more and more used to interpret results of omics data analyses but suffer from compositional (large overlap) and functional (correlated read-outs) redundancy. Moreover, many gene signatures rarely come out as significant in statistical tests. Based on pan-cancer data analysis, we construct a restricted set of 962 signatures defined as informative and demonstrate that they have a higher probability to appear enriched in comparative cancer studies. We show that the majority of informative signatures conserve their weights for the genes composing the signature (eigengenes) from one cancer type to another. We finally construct InfoSigMap, an interactive online map of these signatures and their cross-correlations. This map highlights the structure of compositional and functional redundancies between informative signatures, and it charts the territories of biological functions. InfoSigMap can be used to visualize the results of omics data analyses and suggests a rearrangement of existing gene sets.

An informative collection of gene signatures for transcriptomic data analysis is constructed. The number of transcriptomic signatures grows fast and their collections are highly redundant that hampers omics data analyses interpretation. A computational biology team from Institut Curie led by Andrei Zinovyev selected a collection of 962 gene signatures shown to be informative for cancer studies and reflecting mechanisms of cancer progression. The signatures were filtered from a large compendium without requiring any manual curation by experts through a large-scale unbiased analysis of pancancer data. They have much higher chance to obtain significant enrichment scores in a comparative trancriptomic study. The authors integrated the 962 signatures into InfoSigMap, a new data visualization resource for the interpretation of the results of omics data analyses, which facilitates getting an insight into the mechanisms driving cancer.

A High Ki67/BCL2 Index Could Predict Lower Disease-Free and Overall Survival in Intestinal-Type Gastric Cancer

BACKGROUND

The heterogeneity of gastric cancer makes the identification of potential prognostic indicators particularly important. The Ki67 and BCL2 proteins are known prognostic markers for different types of cancer. Ki67 is associated with cell proliferation, whereas BCL2 has antiproliferative roles. A combined marker based on these opposite functions might provide improved prognostic information in gastric cancer.

METHOD

Ki67 and BCL2 expression was assessed in 276 gastric adenocarcinoma tissue microarrays. A Ki67/BCL2 index based on the relative expression of each protein was divided into low- and high-risk groups using receiver operating characteristic curves.

RESULTS

A high Ki67/BCL2 index significantly correlated with advanced stage, recurrence, intestinal type, high histologic grade, and lymphatic and perineural invasion (all p < 0.05). Univariate and multivariate analyses revealed a significant relationship between disease-free or overall survival and the Ki67/BCL2 index in intestinal-type gastric cancer (all p < 0.05).

CONCLUSIONS

A combined marker using Ki67 and BCL2 could be a useful indicator for predicting survival in patients with intestinal-type gastric cancer.

Apoptotic pathways and stemness in the colorectal epithelium and lamina propria mucosae during the human embryogenesis and carcinogenesis

AIM

Programmed cell death is essential both during normal organ development and carcinogenesis. In this study we immunohistochemically analyzed different pathways of cell death in 11 human conceptuses 5th-10th-weeks old, 10 low and high grade colorectal carcinomas (CRC), and 10 normal colon samples by using markers for apoptosis (caspase-3, AIF, TUNEL), proliferation (Ki-67) and stemness (Oct-4).

RESULTS

Between the 5th and 10th week of development, caspase-3 and AIF showed moderate-to-strong expression in the developing gut wall. During development, number of caspase-3-reactive cells decreased, while AIF increased. While healthy colorectal control and low grade CRC showed moderate expression of caspase-3 and AIF, in high grade CRC their expression was strong. Tumor tissues displayed significantly higher number of positive cells than controls. Occasionally, co-expressing of both markers characterized dying cells. In developing colon, Oct-4 and Ki-67 showed moderate-to-strong expression, while some cells co-expressed both markers. Their number decreased in the epithelium and increased in the connective tissue in later development. Healthy colorectal control displayed moderate Ki-67 and mild Oct-4 reactivity. While in low-grade CRC expression Oct-4 and Ki-67 was moderate, in high-grade CRC their expression was strong. Although Oct-4 and TUNEL occasionally co-expressed in all samples, both grades of CRC contained cells that were Oct-4 positive only.

CONCLUSION

Our study revealed two different parallel pathways of cell death, with characteristic increase of AIF-mediated apoptosis when compared to caspase-3, and presence of stemness cells both during colon development and carcinogenesis. These finding might be considered as important diagnostic, survival and CRC therapy predictors.

High Ki67 expression is an independent good prognostic marker in colorectal cancer

AIMS

To correlate Ki67 expression with outcome in colorectal cancer (CRC).

METHODS

Ki67 labelling index (Ki67LI) was analysed by immunohistochemistry on a tissue microarray containing 1800 CRCs. The results were compared with clinicopathological and molecular parameters.

RESULTS

Ki67LI was considered low in 26.3%, moderate in 56.7% and high in 17.0% of 1653 interpretable CRCs. High Ki67 expression was associated with low tumour stage (p<0.0001) and nodal status (p=0.0315), but not with tumour grade (p=0.8639), histological tumour type (p=0.1542) or tumour localisation, and was an independent prognosticator of favourable survival (p=0.0121). High Ki67 expression was also significantly associated with high-level nuclear β-catenin and p53 expression (p<0.0001 and p=0.0095, respectively).

CONCLUSIONS

In summary, our data show that high Ki67 expression in CRCs is associated with good clinical outcome. Ki67, p53 and β-catenin overexpression seem to be linked to CRC, and indicate a cellular state of high proliferative activity. Finally, our findings strongly argue for a clinical utility of Ki67 immunostaining as an independent prognostic biomarker in CRC.

Ki67 is a promising molecular target in the diagnosis of cancer (review)

The expression of Ki67 is strongly associated with tumor cell proliferation and growth, and is widely used in routine pathological investigation as a proliferation marker. The nuclear protein Ki67 (pKi67) is an established prognostic and predictive indicator for the assessment of biopsies from patients with cancer. Clinically, pKi67 has been shown to correlate with metastasis and the clinical stage of tumors. In addition, it has been shown that Ki67 expression is significantly higher malignant tissues with poorly differentiated tumor cells, as compared with normal tissue. According to its predictive role, pKi67 expression identifies subpopulations of patients who are more likely to respond to a given therapy. The Ki67 labeling index is an independent prognostic factor for survival rate, which includes all stages and grade categories. There is a correlation between the ratio of Ki67‑positive malignant cells and patient survival. It has been shown that blocking of Ki67 either by microinjection of antibodies or through the use of antisense oligonucleotides leads to the arrest of cell proliferation. Specifically, antisense oligonucleotides and antibodies against pKi67 have been shown to inhibit the progression of the cell cycle. The Ki67 protein is well characterized at the molecular level and is extensively used as a prognostic and predictive marker for cancer diagnosis and treatment. Increasing evidence indicates that Ki67 may be an effective target in cancer therapy. It therefore merits further development, including testing in more sophisticated in vitro and appropriate in vivo models. This review provides an overview of recent advances in this field.

Colorectal cancers mimic structural organization of normal colonic crypts

Colonic crypts are stereotypical structures with distinct stem cell, proliferating, and differentiating compartments. Colorectal cancers derive from colonic crypt epithelia but, in contrast, form morphologically disarrayed glands. In this study, we investigated to which extent colorectal cancers phenocopy colonic crypt architecture and thus preserve structural organization of the normal intestinal epithelium. A subset of colon cancers showed crypt-like compartments with high WNT activity and nuclear β-Catenin at the leading tumor edge, adjacent proliferation, and enhanced Cytokeratin 20 expression in most differentiated tumor epithelia of the tumor center. This architecture strongly depended on growth conditions, and was fully reproducible in mouse xenografts of cultured and primary colon cancer cells. Full crypt-like organization was associated with low tumor grade and was an independent prognostic marker of better survival in a collection of 221 colorectal cancers. Our findings suggest that full activation of preserved intestinal morphogenetic programs in colon cancer requires in vivo growth environments. Furthermore, crypt-like architecture was linked with less aggressive tumor biology, and may be useful to improve current colon cancer grading schemes.

Epithelial-mesenchymal transition in carcinomas of the female genital tract

Invasion is a defining feature of malignancy, but the mechanisms of invasion in many common cancers, including gynaecological malignancies, remain unclear. However, it has been proposed that malignant cells may usurp a normal embryological process, epithelial-mesenchymal transition (EMT), as a means of acquiring migratory capacity. The synergistic role of the tumour microenvironment in EMT induction has also been explored and helps to explain the spatially restricted distribution of EMT at the deep tumour margin (invasive front). Furthermore, tumour cells undergoing EMT may acquire cancer stem cell characteristics, and this may be relevant to the entire metastatic process and to tumour recurrence and treatment failure. Nevertheless, doubts persist regarding the role of EMT in malignant progression in vivo, partly because few studies have correlated molecular and histological alterations in clinical pathology specimens. In the current review we summarize the evidence for EMT in the common gynaecological epithelial malignancies, and discuss the morphological and immunohistochemical changes occurring at the invasive tumour front that may represent EMT-like processes. The possibility that carcinosarcomas represent a variant type of EMT with 'fixed' mesenchymal differentiation is also considered. Diagnostic histopathologists are ideally placed to critically evaluate the role of EMT in gynaecological and other types of malignancy.

Biological predictors of survival in stage II colorectal cancer

The routine use of postoperative adjuvant chemotherapy in patients with stage II colorectal cancer is not recommended. However, the incidence of tumor recurrence or distant metastasis in these patients is reported to be 25–35%. The identification of high-risk patients with stage II colorectal cancer remains difficult. Therefore, the aim of this study was to determine the risk factors that may help identify stage II colorectal cancer patients with unfavorable prognosis. Paraffin-embedded tissue samples from 109 patients with stage II colorectal cancer following curative operation were analyzed. Thirteen clinicopathological variables and 5 biological markers were assessed using immunohistochemistry, including p53 (tumor suppressor gene), CD10 (tumor invasion marker), CD34 (angiogenic marker), Ki-67 (cell proliferation index) and CAM 5.2 (marker of lymph node micrometastasis) and investigated for associations with disease-specific survival. Univariate analysis revealed bowel obstruction, lymph node micrometastasis and lymphatic invasion (P<0.01) to be highly significant factors for determining the 5-year disease-specific survival. By contrast, the multivariate analysis revealed lymph node micrometastasis and lymphatic invasion to be independent prognostic factors. Stage II colorectal cancer patients with lymph node micrometastasis and lymphatic invasion may therefore be suitable candidates for adjuvant chemotherapy to improve prognosis.

Low Ki-67 proliferation index is an indicator of poor prognosis in gastric cancer

BACKGROUND AND OBJECTIVES

We designed this study to assess the biologic significance of Ki-67 proliferation index (PI) in gastric cancer.

METHODS

Gastric cancer tissue from 245 patients were immunostained for Ki-67. Ki-67 PI was defined as the percentage of tumor cells positive for Ki-67. In addition, we have previously evaluated the expressions of nine epithelial mesenchymal transition (EMT)-related proteins. The relationship between Ki-67 PI and clinicopathologic parameters, patient survival, and EMT data were sought.

RESULTS

Low Ki-67 PI was correlated with poorly differentiated histology (P = 0.034), an advanced T stage (P < 0.001), and lymph node metastasis (P = 0.011). Also, the low PI group was found to have a significantly worse prognosis than the high PI group (P = 0.003, log-rank test). Multivariate analysis revealed that Ki-67 PI remained as an independent prognostic factor (hazard ratio (95% CI) = 0.670 (0.450-0.999)). Furthermore, greater expressional changes of EMT-related proteins were found to be significantly associated with low Ki-67 PI (P = 0.025).

CONCLUSIONS

These findings suggest that Ki-67 PI is an effective tool for predicting survival in gastric cancer. In addition, we found that an invasive property presented as EMT-related protein expressional changes was inversely correlated with a proliferative activity in gastric cancer.

Restoration of absent in melanoma 2 (AIM2) induces G2/M cell cycle arrest and promotes invasion of colorectal cancer cells

Absent in melanoma 2 (AIM2) is a member of the interferon-inducible HIN-200 protein family. Recent findings point to a role of AIM2 function in both inflammation and cancer. In response to foreign cytoplasmic DNA, AIM2 forms an inflammasome, resulting in caspase activation in inflammatory cells. Moreover, AIM2 reduces breast cancer cell proliferation and mammary tumor growth in a mouse model and shows a high frequency of frameshift mutations in microsatellite unstable (MSI-H) gastric, endometrial and colorectal cancers. However, the consequences of AIM2 restoration in AIM2-deficient colon cancer cells have not yet been examined. Using different constructs for expression of AIM2 fusion proteins, we found that AIM2 restoration clearly suppressed cell proliferation and viability in HCT116 cells as well as in cell lines derived from other entities. In contrast to previous reports from breast cancer cells, our cell cycle analyses of colon cancer cells revealed that AIM2-mediated inhibition of cell proliferation is associated with accumulation of cells at late S-phase, resulting in G2/M arrest. The latter correlated well with upregulation of cyclin D3 and p21(Waf1/Cip1) as well as with inhibition of cdc2 activity through Tyr-15 phosphorylation. Furthermore, AIM2 restoration affected the adhesion of colorectal cancer cells to fibronectin and stimulated the invasion through extracellular matrix-coated membrane in transwell assays. Consistent with this phenotype, AIM2 induced the expression of invasion-associated genes such as VIM and MCAM, whereas ANXA10 and CDH1 were downregulated. Our data suggest that AIM2 mediates reduction of cell proliferation by cell cycle arrest, thereby conferring an invasive phenotype in colon cancer cells.

Assessment of SMAD4, p53, and Ki-67 alterations as a predictor of liver metastasis in human colorectal cancer

PURPOSE

The liver is the most common site of metastasis in patients with colorectal cancer (CRC), and this is a determinant of the prognosis. However, no reliable molecular predictors of liver metastasis have yet been identified.

METHODS

Sixty-two surgical specimens of colorectal cancer were studied. The first group included 25 patients who achieved a disease-free survival period of at least 6 years (CRC-M0), and the second group included 37 patients with synchronous (n = 22) or metachronous (n = 15) liver metastasis (CRC-M1). SMAD4, p53, and Ki-67 expression levels were assessed immunohistochemically.

RESULTS

The loss of SMAD4 expression and elevated Ki-67 expression were found significantly more frequently in CRC-M1 patients than in CRC-M0 patients (P = 0.0047 and P = 0.013, respectively). Statistically significant differences were also observed between the CRC-M0 group and the metachronous metastasis group. No difference was seen in the overexpression of p53 between the groups. A combination analysis of SMAD4 and Ki-67 revealed no cases with maintained levels of SMAD4 and a low Ki-67 expression had or developed liver metastasis.

CONCLUSION

The loss of SMAD4 expression and elevated Ki-67 expression was therefore found to significantly correlate with liver metastasis, regardless of the time of occurrence, thus indicating these factors to be predictive markers for liver metastasis in patients with CRC.

Expression of EZH2 and Ki-67 in colorectal cancer and associations with treatment response and prognosis

Background:

Enhancer of zeste homologue 2 (EZH2) is a member of the Polycomb group of genes that is involved in epigenetic silencing and cell cycle regulation.

Methods:

We studied EZH2 expression in 409 patients with colorectal cancer stages II and III. The patients were included in a randomised study, and treated with surgery alone or surgery followed by adjuvant chemotherapy.

Results:

EZH2 expression was significantly related to increased tumour cell proliferation, as assessed by Ki-67 expression. In colon cancer, strong EZH2 expression (P=0.041) and high proliferation (⩾40%; P=0.001) were both associated with better relapse-free survival (RFS). In contrast, no such associations were found among rectal cancers. High Ki-67 staining was associated with improved RFS in colon cancer patients who received adjuvant chemotherapy (P=0.001), but not among those who were treated by surgery alone (P=0.087). In colon cancers stage III, a significant association between RFS and randomisation group was found in patients with high proliferation (P=0.046), but not in patients with low proliferation (P=0.26). Multivariate analyses of colon cancers showed that stage III (hazard ratio (HR) 4.00) and high histological grade (HR 1.80) were independent predictors of reduced RFS, whereas high proliferation indicated improved RFS (HR 0.55).

Conclusion:

Strong EZH2 expression and high proliferation are associated features and both indicate improved RFS in colon cancer, but not so in rectal cancer.

Slow proliferation as a biological feature of colorectal cancer metastasis

Background:

We have recently reported an inverse relationship between colon cancer progression and tumour proliferative activity. Here, we extend our findings by evaluating the proliferative activity of liver metastatic lesions and primary colorectal cancers (CRC) that differ in their metastatic potential.

Methods:

Using an earlier established multi-gene proliferation signature (GPS), proliferative levels were analysed in 73 primary CRCs and 27 liver metastases.

Results:

Compared with primary CRCs, we observed a significantly lower expression of the GPS in liver metastases and confirmed their lower proliferative levels by quantitative RT–PCR and Ki-67 immunostaining. No difference could be detected in apoptotic indices as assessed by M30 immunostaining, indicating that the net growth rate is lower in metastases relative to primary tumours. Notably, relapsed primaries or those with established metastases had significantly lower proliferative activity than CRCs that were non-metastatic and did not relapse.

Conclusion:

Our results suggest that slow proliferation is a biological characteristic of both liver metastases and those primary tumours with the ability to metastasise. The delineation of the mechanisms underlying the inverse association between proliferation and CRC aggressiveness may be important for the development of new therapeutic strategies.

Molecular and clinico-pathological markers in rectal cancer: a tissue micro-array study

AIMS

The aims of the study were to study the effect of pre-operative treatment on the expression of tumour-related proteins and to correlate the expression of these proteins with response and survival of patients with advanced rectal cancer.

MATERIALS AND METHODS

Tissue micro-arrays from pre- and post-treatment biopsies of 99 patients with rectal cancer treated with pre-operative (chemo)radiotherapy were stained for epidermal growth factor receptor (EGFR), carbonic anhydrase IX, Ki67, vascular endothelial growth factor, cyclo-oxygenase 2 (COX-2) and cleaved cytokeratin 18 (c-CK18). Also, fibro-inflammatory alterations after treatment were evaluated.

RESULTS

Pre-operative (chemo)radiotherapy caused fibro-inflammatory changes, a downregulation of proliferation (Ki67) and EGFR and an upregulation of apoptosis (cleaved CK18). Patients with a good regression during pre-operative treatment showed less proliferating and apoptotic cells in the resection specimen. Multivariate analysis showed that T downstaging, fibro-inflammatory changes in the resection specimen and COX-2 expression in the biopsy correlated with overall survival.

CONCLUSIONS

Pre-operative treatment has an effect on proliferation, apoptosis, inflammation and EGFR expression. The classical clinical parameters as well as fibro-inflammatory changes and COX-2 expression seem most valuable as predictors for survival.

Identification of the molecular mechanisms for dedifferentiation at the invasion front of colorectal cancer by a gene expression analysis

PURPOSE

The aim of this study is to identify gene expression signatures that accompany dedifferentiation at the cancer invasion front in colorectal cancer.

EXPERIMENTAL DESIGN

Two types of colorectal cancer were selected. Both types were well-differentiated adenocarcinomas at the superficial lesion. One type showed a dedifferentiated phenotype at the invasion front (type A, 13 samples); the other showed almost no dedifferentiated cancer cells at the invasion front (type B, 12 samples). Laser microdissection was combined with a cDNA microarray analysis to investigate the superficial lesions and the invasion front in colorectal cancers.

RESULTS

Eighty-three genes were differentially expressed between types A and B in the superficial lesions, and the samples of superficial lesions were divided correctly into two clusters by these genes. Interestingly, the samples of the invasion front were also divided into the two same clusters by these genes. The text mining method selected 10 genes involved in potential mechanisms causing dedifferentiation of cancer cells at the invasion front. The potential mechanisms include the networks of transforming growth factor-beta, Wnt, and Hedgehog signals. The expression levels of 10 genes were calculated by quantitative reverse transcription-PCR and 8 genes were confirmed to be significantly differentially expressed between two types (P < 0.05). The gene expression profiles of 8 genes divided 12 test cases into two clusters with one misclassification.

CONCLUSIONS

The molecular mechanisms constructed with 8 genes from three networks of transforming growth factor-beta, Wnt, and Hedgehog signals were found to correlate with dedifferentiation at the invasion front of colorectal cancer.

The relationship between tumour proliferative activity, the systemic inflammatory response and survival in patients undergoing curative resection for colorectal cancer

BACKGROUND

The aim of the present study was to examine the relationship between Ki-67, C-reactive protein and cancer-specific survival in patients undergoing resection for colorectal cancer.

METHOD

One hundred and forty-seven patients undergoing potentially curative resection for colorectal cancer had preoperative C-reactive protein concentrations and tumour Ki-67 labelling index measured.

RESULTS

On univariate analysis, age (P < 0.001), Dukes stage (P < 0.001), C-reactive protein (P < 0.001) and expression of Ki-67 (< 0.01) were associated with poorer cancer-specific survival. Ki-67 labelling index and C-reactive protein were correlated (r(s) = 0.172, P = 0.037). On multivariate analysis, age (HR 1.96, 95% CI 1.26-3.04, P = 0.003), Dukes stage (HR 4.38, 95% CI 2.11-9.09, P < 0.001) and C-reactive protein (HR 4.09, 95% CI 2.04-8.24, P < 0.001) retained significance.

CONCLUSION

Increased tumour proliferation is associated with a systemic inflammatory response and poor cancer-specific survival in patients undergoing potentially curative surgery for colorectal cancer.

Concurrent EGFr and Cox-2 expression in colorectal cancer: proliferation impact and tumour spreading

BACKGROUND

Many reports were produced on single epidermal growth factor receptor (EGFr) and cyclo-oxygenase-2 (Cox-2) evaluation using immunohistochemical techniques (IHC), but very few works considered concurrent expression of these two proteins in the light of their impact on proliferation and tumour spreading. At least three molecular pathways (EGFr, Cox-2, and APC/beta-catenin molecular cascade) may interact in this malignancy giving rise to cross talking effects on proliferation and cancer spreading.

PATIENTS AND METHODS

To better detail these two latter aggressive features, we studied 205 sporadic colorectal cancer patients, comparing concurrent expression of EGFr, Cox-2, Ki-67, Cyclins D1-A, and E, with tumour spreading (budding) (BUD) and pN status.

RESULTS

Our results point to a different aggressive molecular profile due to Cox-2 expression. Cox-2 High expressing cases showed a clear EGFr proliferation-promoting role. On the contrary, EGFr seems directly involved in cancer cells spreading rather than in promoting cancer proliferation in Cox-2 Low/Negative cases.

CONCLUSIONS

Immunohistochemical profiling of colorectal cancer seems to be a promising approach, not only to define prognostic impact, but also to detail proliferation-related molecular interplays between EGFr and Cox-2 pathways, with these two latter proteins, at present, being the hottest pharmacological targets for colorectal cancer (CRC) chemoprevention and therapy.

Relationship between expression and methylation status of p16INK4a and the proliferative activity of different areas' tumour cells in human colorectal cancer

The p16(INK4a) gene is a cell cycle inhibitor and a major tumour suppressor protein, but the regulation and effects on tumour cells' invasion process of p16(INK4a) is poorly known. A role for p16(INK4a) in basal cell carcinoma is suggested by the observation that p16(INK4a) was upregulated at the invasive front of the majority of basal cell carcinomas with infiltrative growth patterns, accompanied by cessation of proliferation. In this paper, we explore whether there is a difference of tumour cells' proliferative activity between the centre and the invasion front tissues of human colorectal cancer and its relationship with the expression and methylation status of p16(INK4a) gene. We obtained the centre and the invasion front tissues of colorectal cancer respectively by the technology of laser mircodissection. The expressions of the proliferating cell nuclear antigen ki67 and p16(INK4a) were assessed by immunohistochemistry, methylation-specific polymerase chain reaction (MS-PCR) and reverse-transcription polymerase chain reaction (RT-PCR) in the different areas. There was a significant difference in the expressions of ki67 between the centre and the invasion front tissues (p < 0.05). The difference did not correlate with age, sex, Dukes stage but did correlate with expression of p16(INK4a) gene (chi(2) = 25.37, p < 0.01). Furthermore, hypermethylation of the promoter was the major mechanism of inactivation of p16(INK4a) in the centre areas. Demethylation of the p16(INK4a) promoter, the elevated expression of p16(INK4a) protein and mRNA level was proved in the invasion front. Our finding suggested that enhanced invasion in tumours was accompanied by ceased proliferation in the invasion fronts of human colorectal cancer. This interesting phenomenon may be due to not only the microenvironment, but also the molecular changes such as p16(INK4a) status.

Do Proliferating Cell Nuclear Antigen and MIB-1/Ki-67 Have Prognostic Value in Penile Squamous Cell Carcinoma?

OBJECTIVES

To evaluate the role of proliferating cell nuclear antigen (PCNA) and MIB-1/Ki-67 immunohistochemical expression in predicting lymph node metastasis and survival in primary penile squamous cell carcinoma.

METHODS

We conducted a retrospective evaluation of 125 patients with penile squamous cell carcinoma submitted to primary tumor treatment, with information on lymph node status. Clinical and pathologic data for PCNA and MIB-1/Ki-67 expression in the primary tumor were analyzed. Correlations between these data and lymph node metastasis risk and survival were calculated.

RESULTS

In univariate analysis, low MIB-1/Ki-67 expression, the presence of lymphovascular permeation, clinically positive lymph nodes, tumor thickness greater than 5 mm, and infiltration of cavernous bodies were correlated with lymph node metastasis. However, the independent factors for lymph node metastasis risk were PCNA and MIB-1/Ki-67 immunoreactivity, lymphovascular permeation, and N clinical stage. Independent variables for disease-free survival were urethra infiltration and the presence of lymph node metastasis. For death risk evaluation the independent variables were age, lymph node metastasis, and clinical stage.

CONCLUSIONS

There was a correlation between PCNA and MIB1/Ki-67 immunohistochemical expression and the presence of lymph node metastasis. However, PCNA and MIB1/Ki-67 immunohistochemical expression did not have a relationship with survival and death risk.

The invasive front in endometrial carcinoma: higher proliferation and associated derailment of cell cycle regulators

The aim of the study was to explore whether expression of proliferation and hypoxia-related proteins differs in the central parts and the invasive front in endometrial carcinomas. Proliferation-associated proteins Ki67 and cyclin A; cell cycle regulators p16, p21, p53, cyclin D1, cyclin E, and cdk2; and hypoxia-inducible factor 1alpha and its downstream factors glucose transporter 1, carbonic anhydrase IX, and vascular endothelial growth factor were immunohistochemically stained in paraffin-embedded specimens from endometrioid (n = 33), mucinous (n = 1), and serous (n = 5) endometrial carcinomas. The percentages of positive cells at the invasive front and central tumor parts were scored and compared. Ki67 (P < .001), cyclin E (P = .018), p16 (P = .003), and cdk2 (.001) were expressed higher at the invasive front than centrally (Wilcoxon signed ranks test). Higher expression of these antigens at the invasive front was seen in 31 of 38 cases for Ki67, in 16 of 39 cases for cyclin E, in 15 of 39 cases for cdk2, and in 11 of 39 cases for p16. The other cell cycle proteins and the hypoxia-related factors did not show significant differences in expression between the central parts and the invasive front. Endometrial carcinomas clearly show an invasive front that is characterized by higher proliferation and progressive derailment of the cell cycle regulators cyclin E, p16, and cdk2, but not by an increased hypoxic response.

Molecular prognostic markers in resectable colorectal liver metastases: A systematic review

BACKGROUND

Determination of prognosis in patients with resectable colorectal liver metastases (CLM) is desirable in order to improve case selection for surgery and tailor adjuvant treatment according to individual recurrence risk. Conventional clinicopathological factors lack the sensitivity to accurately achieve this goal. Consideration of tumour biology and the identification of molecular prognostic markers may allow more accurate risk stratification.

METHOD

This systematic review examines evidence from published manuscripts looking at molecular markers in resectable colorectal liver metastases and their correlation with disease recurrence and survival following hepatectomy.

RESULTS

Studies have yielded promising results in the search for prognostic molecular markers of CLM. Molecular biomarkers from varied aspects of tumour biology have been examined and a number of these, including proliferation indices, telomerase, thymidylate synthase, microvessel density and thrombospondin-1 appear to have prognostic utility in this context. Validation of other markers, notably p53, has been limited by a failure of methodologies to account for their biological complexity.

CONCLUSIONS

A biomarker-based approach may yield significant benefits through informed treatment of resectable metastatic colorectal malignancy. Standardised retrospective analyses are necessary to confirm preliminary findings and identify existing and novel markers for inclusion into prospective studies. Assessment and verification of multiple molecular markers in this manner may allow molecular profiling of metastases and tailoring of therapy according to the biological aggressiveness of individual tumours. The advent of genomic- and proteomic-based technologies will allow the simultaneous analysis of multiple molecular markers and the derivation of disease profiles associated with disease recurrence and poor survival.

The significance of tumor markers for proliferation and apoptosis in predicting survival in colorectal cancer

PURPOSE

Clinicopathologic staging is even today the best prognostic factor in both colon and rectal cancers. There is still considerable variation in survival within the stages. To find other prognostic indicators we investigated six biologic markers associated with apoptosis and cell proliferation.

METHODS

Formalin-fixed, paraffin-embedded tissue samples of 363 patients with primary colon or rectal cancer of Dukes Stages A to D were chosen for immunohistochemical staining of five tumor markers: bcl-2, p53, Ki-67, cyclin D1, and carcinoembryonic antigen. Also, the number of apoptotic cells was studied by the terminal deoxynucleotidyl transferase-mediated D: -UTP nick end labeling method in 347 cases. The study was done on specially prepared tissue arrays.

RESULTS

In rectal cancer, patients with a Ki-67 labeling index of 5 percent or higher had a better prognosis than those with a lower index. Also, positive cytoplasmic p53 expression predicted a favorable outcome in rectal cancer. In colon cancer, positive nuclear staining of cyclin D1 reflected better survival. Weak and moderate staining of carcinoembryonic antigen correlated with better prognosis than strong staining, but negative staining predicted poor outcome. High apoptotic index of 100 or higher correlated with poor prognosis in colon cancer. However, in rectal cancer, the trend was the opposite. Bcl-2 staining tended to be more intense in samples of patients living 5 years or longer compared with those with worse prognosis.

CONCLUSIONS

Colon cancer and rectal cancer seem to have different biologic behavior, at least with respect to apoptosis, cytoplasmic p53 expression, and perhaps Ki-67 and carcinoembryonic antigen. Further studies are needed to clarify the significance of these factors.

Increased proliferation activity measured by immunoreactive Ki67 is associated with survival improvement in rectal/recto sigmoid cancer

AIM: To assess the expression of Ki67 as prognosticator in rectal/recto sigmoid cancer.

METHODS: Samples from 146 patients with rectal and recto sigmoid cancer were studied for expression of Ki67 and its prognostic significance in comparison with clinico-pathological predictors of survival. Formalin-fixed, paraffin-embedded tissues from 6 (4.1%) patients with T1, 26 (17.8%) with T2, 94 (64.4%) with T3, and 20 (13.7%) with T4 tumors were studied. Ki67 expression was determined immunohistochemically. Samples were divided according to mean value into high (>40%) and low (≤40%) expression. Areas of extensive proliferation (>50%) were defined as ‘hot spot’ areas.

RESULTS: Hot spot areas were present in samples regardless of histopathological grade. Lower TNM and Dukes stage and higher expression of Ki67 and presence of Ki67 hot spot areas in histopathological samples were associated with better survival, whereas no association was observed with histopathological grade (P = 0.78). In Cox multivariate regression analysis, significant prognostic factors were Dukes stage (P<0.001), presence of lymph node metastases (P = 0.015), age (P = 0.035) and presence of Ki67 hot spot areas (P = 0.044).

CONCLUSION: Proliferative activity as measured by Ki67 in rectal cancer is associated with survival improvement compared with patients with low Ki67. Areas of prognostically significant increased proliferation were found independently of histopathological tumor grade.

[Current status of the prognostic value of molecular markers in patients with colorectal cancer and the prediction of response to adjuvant therapy]

Colorectal cancer is one of the best studied of all malignant diseases in terms of genetics and/or molecular prognostic factors. These factors, and relationships with prognosis, may have important implications especially in the design of surgical and adjuvant chemo-radiotherapy options. However, the true prognostic significance of all known factors has yet to be realised. We have reviewed the literature with specific focus on the role of molecular markers involved in prognosis and the prediction of response to adjuvant treatment.

Thymidylate synthase expression, p53, bcl-2, Ki-67 and p27 in colorectal cancer: relationships with tumor recurrence and survival

It was the objective to determine in this retrospective study whether thymidylate synthase (TS), p53, bcl-2, Ki-67 and p27 in Dukes' stage B and stage C (AJCC/UICC stage II and III) colorectal adenocarcinoma were predictive of disease-free survival (DFS) and overall survival (OS). Paraffin-embedded specimens from 103 patients with colorectal cancer, treated with surgery between October 1994 and September 1999, were examined for TS expression, p53, bcl-2, Ki-67 and p27 using immunohistochemistry; 51 cases were Dukes' stage B and 52 cases were Dukes' stage C disease. Adjuvant 5-FU-based chemotherapy was given to all patients, while 31 having rectal malignancy also received pelvic radiotherapy. Data were associated with the recurrence rate and survival. With a median follow-up of 5 years, 38 patients (36.8%) developed recurrence and as many patients (36.8%) died. TS was overexpressed in 16 cases (15.6%), p53 nuclear oncoprotein accumulation in >10% of cells occurred more frequently [61 of 103 cases (59.3%)], positive expression of bcl-2 protein in >10% of cells was observed in 41 of 103 cases (39.9%), 57 patients (55.4%) showed immunohistochemical expression of Ki-67 and there were 75 cases (72.9%) with p27 accumulation. The pathological stage was the only independent prognostic factor for DFS (p = 0.042). Sex, as well as age and biological prognostic factors, had no significant impact value on DFS and OS. A multivariate analysis of OS demonstrated that stage C, p53 negative and Ki-67 positive were associated significantly with an unfavorable outcome and a worse median OS (p = 0.035 and t ratio = 2.48). Some biological characteristics such as p53 and Ki-67 status may provide useful prognostic information in addition to the classical clinicopathological parameters. However, further studies are needed to clarify the value of adopting biological prognostic factors into clinical practice.

Expression profiling of colorectal carcinomas using tissue microarrays: cell cycle regulatory proteins p21, p27, and p53 as immunohistochemical prognostic markers in univariate and multivariate analysis

With the rapidly growing understanding of tumor biology, molecular staging of cancer is expected to improve prognostication. This would be particularly important for cancers amenable to adjuvant treatment, such as colorectal carcinomas. To generate data for this, the tissue microarray technique may prove useful. Tissue microarrays were constructed with triplicate cores (0.6 mm diameter) from the invasive margins of a consecutive single-institution series of 184 colorectal carcinomas. Immunostaining for p53, p21, p27, Ecadherin, and beta-catenin was scored. Tumor cell proliferation was assessed by mitotic indices and Ki-67 labeling, apoptosis by quantification of apoptotic bodies. Reduced nuclear immunostaining for p21 (<10%) and p27 (< or =50%) and reduced membranous expression of Ecadherin were significantly associated with a poorer clinical course by univariate analysis. beta-catenin immunostaining had no prognostic impact. Mitotic and apoptotic indices as well as Ki-67 labeling below the median were indicators of poor prognosis. Complete absence of p53 nuclear staining was a significant adverse prognostic factor. By Cox regression, p53 = 0%, p53 = 0%, in combination with p27 < or = 50%, the mitotic index and the combined mitotic and apoptotic index added prognostic information to UICC stage. The authors found that growth pattern, lymphohistiocytic response, lymphatic permeation, and venous spread, too, each was a strong prognosticator in addition to UICC stage. The results support that tissue microarrays are a useful tool for screening immunohistochemical markers for prognostic use. An immunopanel of p21, p27, and p53 could be useful for prognostication in colorectal carcinoma in addition to UICC stage.

High-level mRNA quantification of proliferation marker pKi-67 is correlated with favorable prognosis in colorectal carcinoma

PURPOSE

The present study retrospectively examines the expression of pKi-67 mRNA and protein in colorectal carcinoma and their correlation to the outcome of patients.

METHODS

Immunohistochemistry and quantitative RT-PCR were used to analyze the expression of pKi-67 in 43 archival specimens of patients with curatively resected primary colorectal carcinoma, who were not treated with neo-adjuvant therapy.

RESULTS

We determined a median pKi-67 (MIB-1) labeling index of 31.3% (range 10.3-66.4%), and a mean mRNA level of 0.1769 (DeltaC(T): range 0.01-0.69); indices and levels did not correlate. High pKi-67 mRNA DeltaC(T) values were associated with a significantly favorable prognosis, while pKi-67 labeling indices were not correlated to prognostic outcome. A multivariate analysis of clinical and biological factors indicated that tumor stage (UICC) and pKi-67 mRNA expression level were independent prognostic factors.

CONCLUSION

Quantitatively determined pKi-67 mRNA can be a good and new prognostic indicator for primary resected colorectal carcinoma.

In vivo imaging of cellular proliferation in colorectal cancer using positron emission tomography

BACKGROUND

and aims: Positron emission tomography (PET) using (18)F labelled 2-fluoro-2-deoxy-D-glucose ((18)FDG) is an established imaging tool, although the recent development of a biologically stable thymidine analogue [18F] 3'-deoxy-3-fluorothymidine ((18)FLT) has allowed PET to image cellular proliferation by utilising the salvage pathway of DNA synthesis. In this study, we have compared uptake of (18)FLT and (18)FDG with MIB-1 immunohistochemistry to evaluate the role of PET in quantifying in vivo cellular proliferation in colorectal cancer (CRC).

PATIENTS AND METHODS

Patients with resectable, primary, or recurrent CRC were prospectively studied. Thirteen lesions from 10 patients (five males, five females), median age 68 years (range 54-87), were evaluated. Patients underwent (18)FDG and (18)FLT PET scanning. Tracer uptake within lesions was quantified using standardised uptake values (SUVs). Histopathological examination and MIB-1 immunohistochemistry were performed on all lesions, and proliferation quantified by calculating a labelling index (% of MIB-1 positively stained nuclei within 1500 tumour cells).

RESULTS

Histology confirmed adenocarcinoma in 12 of 13 lesions; the remaining lesion was reactive. All eight extrahepatic lesions were visualised using both (18)FLT and (18)FDG. Three of the five resected liver metastases were also avid for (18)FLT and showed high proliferation, while the remaining two lesions which demonstrated no uptake of (18)FLT had correspondingly very low proliferation. There was a statistically significant positive correlation (r =0.8, p<0.01) between SUVs of the tumours visualised with (18)FLT and the corresponding MIB-1 labelling indices. No such correlation was demonstrated with (18)FDG avid lesions (r =0.4).

CONCLUSIONS

(18)FLT PET correlates with cellular proliferation markers in both primary and metastatic CRC. This technique could provide a mechanism for in vivo grading of malignancy and early prediction of response to adjuvant chemotherapy.

P27 does not predict histopathological response to radiochemotherapy in rectal cancer

BACKGROUND

Tumor response to radiochemotherapy (RCT) varies considerably, even among patients treated in accordance with the same protocol. The aim of the present study was to test the predictive value of the cell-cycle inhibitor p27kip1 with regard to neoadjuvant RCT response in rectal cancer.

MATERIALS AND METHODS

P27kip1 was evaluated by immunohistochemistry in pretreatment biopsy material obtained from 42 patients with rectal cancer treated uniformly in accordance with an identical prospective neoadjuvant RCT protocol (CAO/AIO/ARO-94). Four expression patterns (staining intensity [-,+,++,+++] and the percentage of positive cells, evaluated separately for nuclei and cytoplasm) of p27kip1 were investigated for correlation with tumor response, which was assessed in the resected surgical specimen using a histopathological five-point grading system. Additionally, p27(kip1) expression was investigated for correlation with several pathological features, overall survival, and disease-free survival.

RESULTS

p27kip1 expression was as follows: nuclear intensity: -: 8, +: 19, ++: 11, +++: 4 cases, median percentage of positive cells: 18.75%; cytoplasmic intensity: -: 0, +: 25, ++: 12, +++: 3 cases, median percentage of positive cells: 70%. Histopathological tumor regression was acceptable in 30 patients (3 complete; 27 good) and inadequate in 12 patients (7 moderate; 5 minimal). No tumor failed to show some regression. No significant correlation was found between any of the p27kip1 expression patterns and RCT response, tumor differentiation (low grade versus high grade), cT- and ypT-category, UICC stage, overall survival, and disease-free survival.

CONCLUSIONS

p27kip1 cannot aid the individualization of multimodal treatment strategies in rectal cancer, nor can it serve as a predictor of survival.