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

ASF1B acted as a prognostic biomarker for stomach adenocarcinoma

Stomach adenocarcinoma (STAD) has a high mortality rate due to the lack of highly sensitive biomarkers. Therefore, the search for potential tumor markers is of great value. ASF1B is a prognostic marker for a variety of tumors, while the prognostic value and immune microenvironment of ASF1B in STAD remain unclear, and to be determined. Kaplan-Meier analysis was performed to analyze the prognostic role of ASF1B in STAD. Functional enrichment of ASF1B was explored with GO and KEGG pathway analysis. We also explored the correlation between ASF1B expression and immune infiltration in STAD. ASF1B was significantly upregulated in STAD tissues and high expression of ASF1B indicated a poor overall survival, progression-free survival, and first progression rate in STAD. The functional enrichment analysis of ASF1B and related genes showed high enrichment in the cell cycle and DNA repair, and the ASF1B high expression group was also mainly enriched in pathways such as the cell cycle. Analysis of tumor immune infiltration showed that ASF1B expression was significantly associated with the majority of immune cell infiltration in STAD. Moreover, STAD patients with high ASF1B expression had a higher tumor mutation burden score, microsatellite instability score, PD-1 immunophenoscore, and immune checkpoint expression. Our results suggest that ASF1B was an independent prognostic factor for STAD as well as a potential target for immunotherapy.

Identification of a seven-cell cycle signature predicting overall survival for gastric cancer

While genetic alterations in several regulators of the cell cycle have a significant impact on the gastric carcinogenesis process, the prognostic role of them remains to be further elucidated. The TCGA-STAD training set were downloaded and the mRNA expression matrix of cell cycle genes was extracted and corrected for further analysis after taking the intersection with GSE84437 dataset. Differentially expressed mRNAs were identified between tumor and normal tissue samples in TCGA-STAD. Univariate Cox regression analysis and lasso Cox regression model established a novel seven-gene cell cycle signature (including GADD45B, TFDP1, CDC6, CDC25A, CDC7, SMC1A and MCM3) for GC prognosis prediction. Patients in the high-risk group shown significantly poorer survival than patients in the low-risk group. The signature was found to be an independent prognostic factor for GC survival. Nomogram including the signature shown some clinical net benefit for overall survival prediction. The signature was further validated in the GSE84437 dataset. In tissue microarray, CDC6 and MCM3 protein expression were significant differences by the immunohistochemistry-based H-score between tumor tissues and adjacent tissues, and CDC6 is an independent prognostic factor for GC. Interestingly, our GSEA revealed that low-risk patients were more related to cell cycle pathways and might benefit more from therapies targeting cell cycle. Our study identified a novel robust seven-gene cell cycle signature for GC prognosis prediction that may serve as a beneficial complement to clinicopathological staging. The signature might provide potential biomarkers for the application of cell cycle regulators to therapies and treatment response prediction.

Clinicopathological significance and prognostic value of P27 expression in gastric cancer patients: a meta-analysis

Loss of P27 expression correlates with clinical progression in a variety of human cancers. However, the correlation between P27 expression and gastric cancer remains controversial. In this meta-analysis, we performed an electronic search based on six databases to select a sufficient number of studies. Pooled hazard ratio (HR) was used as estimates to investigate the association between P27 expression and prognosis of patients with gastric cancer. We identified 19 studies with 2387 gastric cancer patients, ranging between 50 and 316 samples per study. Q and I2 tests demonstrated that the homogeneity among 19 studies (I2 = 47%, P = 0.0004), thus we applied a fixed-effects model to calculate the pooled HR of P27expression and overall survival (OS) of gastric cancer patients was 0.68, and 95% confidence interval (CI) was 0.60-0.78. Next, we conducted a subgroup meta-analysis and found that patients with low P27 expression in Asians (HR = 0.69, 95% CI: 0.58-0.82) and non-Asians (HR = 0.57, 95% CI: 0.41-0.79) had poor prognosis. In addition, we found the publication bias results of OS in the final included 19 studies showed that this funnel plot presented incomplete symmetry, and then removed three literatures with larger HRs bias, and found that the remaining 16 literatures were homogeneity (I2 = 0%, P = 0.47), the pooled HR was 0.52 with 95% CI of 0.43-0.62, and the publication bias disappeared. These results suggested a strong association between P27 underexpression and poorer prognosis of gastric cancer in patients. P27 may be a tumor suppressor for predicting survival outcome of gastric cancer patients.

Significant function and research progress of biomarkers in gastric cancer

Gastric cancer is one of the most common gastrointestinal tumor types, and the incidence and mortality rates are higher in men compared with women. Various studies have revealed that gastric cancer is a spectrum of tumor types, which have biological and genetic diversity. It has proven to be difficult to improve the overall survival and disease-free survival of patients with gastric cancer through the use of traditional surgery and chemoradiation, as gastric cancer is usually identified at an advanced stage. In consequence, the outcome is frequently poor. Thus, novel biomarkers and anticancer targets are required to improve the outcome. As the identification of biomarkers has increased due to advances in research and the greater availability of bioinformatics and functional genomics, the potential therapeutic regimens available have also increased concurrently. These advances have also improved the ability to predict responses to chemotherapy, targeted therapy and immunotherapy, whilst other biomarkers predict post-treatment survival and recurrence based on their expression. This review focuses closely on the important functions of biomarkers in the timely diagnosis and treatment of gastric cancer, in addition to the advances in the study of certain novel markers in gastric cancer.

Suppression of AURKA alleviates p27 inhibition on Bax cleavage and induces more intensive apoptosis in gastric cancer

Bax is a key molecule in mitochondria-apoptosis pathway, however it is not always an efficient apoptosis inducer in chemotherapeutic agents-treated cancer cells. Here, we found that specific inhibition of AURKA by MLN8237-induced calpain-mediated Bax cleavage at N-terminal 33th asparagine (c-Bax) to promote apoptosis. The c-Bax, as Bax, could also efficiently located to mitochondria but c-Bax is a stronger apoptosis inducer than Bax. Morever, c-Bax-induced apoptosis could not be blocked by the canonical Bax inhibitor, Bcl-2. Further study found p27 was degraded and subsequently Bax was transformed to c-Bax through calpain. Also, p27 efficiently inhibited Bax cleavage and p27 knockdown sensitized apoptosis through Bax cleavage when cancer cells were treated with MLN8237. It is also demonstrated that the anti-apoptotic role of p27 lies its cytoplasmic localization. Finally, we found that the positive correlation between AURKA and p27 in advanced gastric cancer patients. In conclusion, we found that MNL8237 suppressed cell growth by regulating calpain-dependent Bax cleavage and p27 dysregulation in gastric cancer cells.

Molecular Signaling in Tumorigenesis of Gastric Cancer

Gastric cancer (GC) is regarded as the fifth most common cancer and the third cause of cancer-related deaths worldwide. Mechanism of GC pathogenesis is still unclear and relies on multiple factors, including environmental and genetic characteristics. One of the most important environmental factors of GC occurrence is infection with Helicobacter pylori that is classified as class one carcinogens. Dysregulation of several genes and pathways play an essential role during gastric carcinogenesis. Dysregulation of developmental pathways such as Wnt/β-catenin signaling, Hedgehog signaling, Hippo pathway, Notch signaling, nuclear factor-kB, and epidermal growth factor receptor have been found in GC. Epithelial-mesenchymal transition, as an important process during embryogenesis and tumorigenesis, is supposed to play a role in initiation, invasion, metastasis, and progression of GC. Although surgery is the main therapeutic modality of the disease, the understanding of biological processes of cell signaling pathways may help to develop new therapeutic targets for GC.

The Pattern of Signatures in Gastric Cancer Prognosis

Gastric cancer is one of the most common malignancies worldwide and it is a fourth leading cause of cancer-related death. Carcinogenesis is a multistage disease process specified by the gradual procurement of mutations and epigenetic alterations in the expression of different genes, which finally lead to the occurrence of a malignancy. These genes have diversified roles regarding cancer development. Intracellular pathways are assigned to the expression of different genes, signal transduction, cell-cycle supervision, genomic stability, DNA repair, and cell-fate destination, like apoptosis, senescence. Extracellular pathways embrace tumour invasion, metastasis, angiogenesis. Altered expression patterns, leading the different clinical responses. This review highlights the list of molecular biomarkers that can be used for prognostic purposes and provide information on the likely outcome of the cancer disease in an untreated individual.

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.

Biomarkers for gastric cancer: Progression in early diagnosis and prognosis (Review)

Gastric cancer is one of leading causes of cancer-related mortality worldwide and is a notable disease due to its heterogeneity. Recently, numerous studies have investigated the molecular basis of gastric cancer, involving the alteration of pathogenesis, and invasion and metastasis. With the development of modern technologies, various novel biomarkers had been identified that appear to possess diagnostic and prognostic value; therefore, the present review describes our current knowledge of biomarkers for the early diagnosis and prognosis of gastric cancer. Classic biomarkers for gastric cancer diagnosis include carcinoembryonic antigen and cancer antigen 19-9, while microRNA and DNA hypomethylation are proposed as novel biomarkers. Excluding classical biomarkers, biomarkers for determining the progression and prognosis of gastric cancer focus on targeting microRNAs, epigenetic alterations and genetic polymorphisms.

Ablation of galectin-3 induces p27(KIP1)-dependent premature senescence without oncogenic stress

Premature senescence induced by oncogenic stimuli or tumor suppressor activation plays opposing roles in tumorigenesis. Here, we propose that galectin-3, a β-galactoside-binding lectin, regulates premature senescence without oncogenic stress. We detected premature senescence, decreased Skp2, and increased p27^KIP1 expression in galectin-3 knockout MEFs and galectin-3-depleted gastric cancer cells. Interestingly, galectin-3 depletion did not affect other senescence inducers such as p14^ARF, p16^INK4A, and p21^WAF1/CIP1, suggesting that galectin-3-regulated senescence is p27^KIP1 dependent. We demonstrate that galectin-3 depletion decreases retinoblastoma protein (Rb) phosphorylation (Ser780, Ser807/811), cyclin D1 and CDK4 expression, and E2F1 transcriptional activation. Galectin-3 directly interacts with the cyclin D1/CDK4 complex and promotes hyperphosphorylation of Rb. It also blocks the inhibition of E2F1 transcription, thereby increasing the expression of Skp2 and reducing the stability of p27^KIP1 to promote the proliferation of gastric cancer cells. Xenograft mice with galectin-3-depleted gastric cancer cells display tumor growth retardation that is reversed by Skp2 overexpression. Increased expression of galectin-3 is also associated with the advanced TNM (tumor, lymph node, metastasis) system, clinicopathological stage, and lymph node metastases. The probability of survival was significantly decreased in gastric cancer patients with galectin-3^high p27^KIP1-lowcells. Taken together, our results show that galectin-3 may accelerate gastric tumorigenesis by inhibiting premature senescence.

Promoter methylation‑associated silencing of p27kip1 gene with metastasis in esophageal squamous cell carcinoma

The aim of the present study was to determine the frequency of p27kip1 promoter methylation in esophageal squamous cell carcinoma (ESCC). The methylation status of the p27kip1 promoter was analyzed by methylation‑specific polymerase chain reaction (MSP) in 50 ESCC and matched non‑tumor tissues. Cell lines were treated with the demethylation agent 5‑aza‑2'‑deoxycytidine (5‑Aza‑CdR) and p27kip1 mRNA expression was detected by quantitative polymerase chain reaction. p27kip1 methylation was found in 36% (18/50) of ESCC patients, but only in 12% (6/50) of the corresponding non‑tumor tissues (P=0.005). There were statistically significant associations between the presence of methylation and tumor metastasis (P=0.002). The p27kip1 mRNA was lower in ESCC compared with non‑tumor tissues (mean ± standard deviation, ‑0.886±3.298 vs. 0.988±0.257; P=0.0033). Furthermore, a significant association was identified between the methylation status of the p27kip1 promoter and p27kip1 mRNA expression in the tissue (P<0.01). Thus, demethylation by 5‑Aza‑CdR was capable of inducing p27kip1 mRNA expression in esophageal cancer cell lines. The high promoter methylation of p27kip1 is a common phenomenon in ESCC, which may be an important mechanism of silencing p27kip1 mRNA expression.

Molecular biomarkers in esophageal, gastric, and colorectal adenocarcinoma

Cancers of the esophagus, stomach and colon contribute to a major health burden worldwide and over 20% of all cancer deaths. Biomarkers that should indicate pathogenic process and are measureable in an objective manner for these tumors are rare and not established in the clinical setting. In general biomarkers can be very useful for cancer management as they can improve clinical decision-making regarding diagnosis, surveillance, and therapy. Biomarkers can be different types of molecular entities (such as DNA, RNA or proteins), which can be detected, in different tissues or body fluids. However, more important is the type of biomarker itself, which allows diagnostic, prognostic or predictive analyses for different clinical problems. This review aims to systematically summarize the recent findings of genetic and epigenetic markers for gastrointestinal tumors within the last decade. While many biomarkers seem to be very promising, especially if used as panels, further development is urgently needed to address practical considerations of biomarkers in cancer treatment.

Genomic and genetic alterations influence the progression of gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, although the incidence has gradually decreased in many Western countries. Two main gastric cancer histotypes, intestinal and diffuse, are recognised. Although most of the described genetic alterations have been observed in both types, different genetic pathways have been hypothesized. Genetic and epigenetic events, including 1q loss of heterozygosity (LOH), microsatellite instability and hypermethylation, have mostly been reported in intestinal-type gastric carcinoma and its precursor lesions, whereas 17p LOH, mutation or loss of E-cadherin are more often implicated in the development of diffuse-type gastric cancer. In this review, we summarize the sometimes contradictory findings regarding those markers which influence the progression of gastric adenocarcinoma.

Clinical significance of P27 and PCNA expression in hilar cholangiocarcinoma

AIM: To analyze the clinical significance of P27 and proliferating cell nuclear antigen (PCNA) expression in hilar cholangiocarcinoma.

METHODS: The expression of P27 and PCNA was detected by immunohistochemistry in 44 hilar cholangiocarcinoma specimens and 8 normal bile duct tissue specimens.

RESULTS: The positive rates of P27 and PCNA expression in hilar cholangiocarcinoma were 77.2% and 100%, respectively. P27 expression had a significant correlation with histological grade, lymph node metastasis and perineural invasion. PCNA expression was associated with histological grade, lymph node metastasis and vascular invasion. The survival of patients with low or absent P27 expression was significantly lower than that of patients with high P27 expression. PCNA expression in grade III and IV cancer was associated with poor survival when compared with that in grade II cancer.

CONCLUSION: P27 and PCNA expression is associated with the development and progression of hilar cholangiocarcinoma and can be used as prognostic markers for the disease.

Dysregulation of cellular signaling in gastric cancer

The pathogenesis of gastric cancer is complex and related to multiple factors. Dysregulation of intracellular signaling pathways represents a common pathogenic mechanism and may be amenable to drug targeting. Multiple well-established oncogenic pathways, such as those mediated by cell cycle regulators, nuclear factor-kappaB, cyclooxygenase-2 and epidermal growth factor receptor are implicated in gastric carcinogenesis. Emerging evidence also underscores the importance of signaling pathways involved in the developmental process, including transforming growth factor-beta/bone morphogenetic protein signaling, Wnt/beta-catenin signaling, Hedgehog signaling and Notch signaling. Understanding their biological significance will provide a rational basis for drug development. Their relative importance and cross-talk in gastric carcinogenesis, however, are still not completely understood and warrant further investigation.

BCL6 degradation caused by the interaction with the C-terminus of pro-HB-EGF induces cyclin D2 expression in gastric cancers

BCL6 is a transcriptional repressor that has important functions in lymphocyte differentiation and lymphomagenesis, but there have been no reports of BCL6 expression in gastric cancers. In the present study, we investigated the BCL6 function in gastric cancers. Treatment with TPA resulted in BCL6 degradation and cyclin D2 upregulation. This phenomenon was inhibited by the suppression of the nuclear translocation of HB-EGF-CTF (C-terminal fragment of pro-HB-EGF). The HB-EGF-CTF nuclear translocation leads to the interaction of BCL6 with HB-EGF-CTF and the nuclear export of BCL6, and after that BCL6 degradation was mediated by ubiquitin/proteasome pathway. Real-time RT-PCR and siRNA targeting BCL6 revealed that BCL6 suppresses cyclin D2 expression. Our data indicate that BCL6 interacts with nuclear-translocated HB-EGF-CTF and that the nuclear export and degradation of BCL6 induces cyclin D2 upregulation. We performed immunohistochemical analyses of BCL6, HB-EGF and cyclin D2 in human gastric cancers. The inverse correlation between BCL6 and cyclin D2 was also found in HB-EGF-positive human gastric cancers. BCL6 degradation caused by the HB-EGF-CTF also might induce cyclin D2 expression in human gastric cancers. Inhibition of HB-EGF-CTF nuclear translocation and maintenance of BCL6 function are important for the regulation of gastric cancer progression.

Comparison of chromosomal aberrations between primary tumors and their synchronous lymph-node metastases in intestinal-type gastric carcinoma

Lymph-node metastasis is a main factor causing poor prognosis of patients with gastric cancer (GC). In order to determine the genes involved in lymph-node metastasis, we compared primary tumors with their synchronous lymph-node metastases for DNA sequence copy number aberrations (DSCNAs) in 20 patients diagnosed as having intestinal-type GC using comparative genomic hybridization (CGH). The results showed that some DSCNAs (gains at 8q, 13q, 5p, 7 and X, and losses at 1p, 17p, 19, 21q and 22q) were frequently found in both primary tumors and their metastases. However, metastases often contained DSCNAs that were not found in corresponding primary tumors, and gain at 20q12-13 and losses at 21qcen-21, 4q and 14q22-ter were significantly more frequently observed in metastatic lesions than in their primary tumors (10:2, 9:0, 6:0, and 7:0 between metastases and corresponding primary tumors, respectively). Our data indicate that gain at 20q12-13 and losses at 21qcen-21, 4q, and 14q22-ter are involved in lymph-node metastases, and that these chromosomal regions may contain the genes related to lymph-node metastases in intestinal-type GC.

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.

Clinicopathologic significance of an immunohistochemical expression of p27 in scirrhous carcinoma of the breast

BACKGROUND

Scirrhous carcinoma has been known to have more aggressive biological behavior than other histologic subtypes of invasive ductal carcinoma of the breast. The significance of expression of p27kip1, which is thought to be a tumor suppressor gene, in breast carcinoma remains controversial. The aim of the current study was to clarify clinicopathologic significance of scirrhous carcinoma of the breast with special reference to p27 expression.

METHODS

Clinicopathologic features including immunohistochemical expression of p27 were compared between scirrhous carcinoma (n=42) and non-scirrhous invasive ductal carcinoma (papillotubular and solid-tubular carcinoma, n=63) of the breast.

RESULTS

The proportion of pathologic lymph node metastasis among scirrhous carcinomas was significantly higher than that among carcinomas of other histologic types (papillotubular or solid-tubular carcinomas, p=0.029). The proportion of strong expression of p27 among scirrhous carcinomas was significantly lower than that among tumors of other histologic types (p<0.0001).

CONCLUSIONS

Biological behavior of scirrhous carcinoma was found to be aggressive. The aggressiveness and poor cellular differentiation of scirrhous carcinoma of the breast might be related to low p27 expression.

Id-1 gene downregulation by sulindac sulfide and its upregulation during tumor development in gastric cancer

The molecular mechanisms underlying the chemopreventive effects of NSAIDs are not well understood and remain the subject of debate. One of the mechanistic possibilities involves alterations in gene expression. We examined gene expression profiles in SNU601 gastric cancer cells treated with sulindac sulfide (50 microM) for 24 hr. Microarray analysis showed that 1.3% (105/8170) of genes were induced or repressed more than 3-fold in cells treated with sulindac sulfide. Seven genes were selected and confirmed by reverse transcription-polymerase chain reaction. Inhibitor of differentiation/DNA binding-1 (Id-1) was downregulated in SNU601 cells treated with sulindac sulfide. Id-1 expression level was decreased dose-dependently by sulindac sulfide. In addition, the expression pattern of Id-1 was inversely related to that of nm23. We also examined Id-1 expression in human gastric cancer tissues and compared it with clinicopathologic parameters to study its biologic role in the cancers. Id-1 was frequently and strongly expressed in gastric cancer tissues compared with that in adjacent nonmetaplastic mucosa. Its immunoreactivity scores were positively correlated to Ki67 labeling indices and tumor progression, and is higher in intestinal type than in diffuse type. In summary, a number of genes, both induced and repressed, could be important in mediating sulindac sulfide-induced cell death in gastric cancer cells. Id-1, one of the repressed genes, is upregulated in gastric cancers and has positive role in tumor progression and histogenesis of intestinal-type cancers.

Prognostic significance of p21WAF1/CIP1, p27Kip1, p53 and E-cadherin expression in gastric cancer

BACKGROUND

Gastric carcinoma is characterised by numerous genetic and epigenetic alterations that influence cell cycle progression, apoptosis and DNA repair. These alterations include down-regulation of the cyclin-dependent kinase (CDK) inhibitors p21(WAF1/CIP1) and p27(Kip1), and mutations of the tumour suppressor protein p53 and the cell adhesion molecule E-cadherin. Combined evaluation of the prognostic significance of these alterations has not been reported in Mexican Mestizo patients.

AIMS

To evaluate p21(WAF1/CIP1), p27(Kip1), p53 and E-cadherin protein expression, including mutant E-cadherin variants with deletion of exon 8 (del 8) or 9 (del 9), in gastric cancer from Mexican patients.

METHODS

Immunohistochemistry for the above-mentioned markers, including mutation-specific E-cadherin antibodies, was carried out in 69 gastric carcinomas; expression levels were correlated with histotype, tumour stage and prognosis.

RESULTS

Expression of p21(WAF1/CIP1) alone or in combination with p27(Kip1) or in the absence of p53 was associated with favourable prognosis. Staining of del 8 and del 9 E-cadherin was found exclusively in patients negative for p53 and positive for p21(WAF1/CIP1), suggesting that the p21(WAF1/CIP1) regulatory function of p53 was intact.

CONCLUSION

Combined evaluation of the prognostic significance of cell cycle regulators and E-cadherin should be performed. Even though patients negative for p53 and positive for p21(WAF1/CIP1) have a favourable prognosis, it may have a negative influence on prognosis if they acquire in addition E-cadherin mutations which have been shown previously to be associated with poor survival.

Gene expression profile of primary gastric cancer: towards the prediction of lymph node status

BACKGROUND

The identification of gastric tumors associated with a higher risk of lymph node metastasis could help surgeons select patients who may benefit from extended lymph node dissection. The aim of this study was to screen the genome in the search of primary gastric cancer gene expression profiles that might predict lymph node status.

METHODS

The gene expression profile was evaluated in frozen tumor samples obtained from 32 patients with primary gastric adenocarcinomas. The array consisted of a duplicated spot panel of 5,541 human genes. To classify node-positive (N+) and node-negative (N-) cases, a logistic regression model was fitted optimizing the Akaike Information Criteria after a stepwise gene selection. The accuracy was evaluated by means of leave-one-out cross validation.

RESULTS

All patients underwent radical gastrectomy and extended lymphadenectomy. Of all the cases, 21 were N+ and 11 demonstrated no lymph node involvement (N-). After quality filtering, the analysis of variance selected a set of 136 genes potentially correlated with nodal involvement (P value <.05). Of these 136 genes, 5 were differentially expressed (adjusted P value <.05). After a stepwise gene selection, only three genes (Bik, aurora kinase B, eIF5A2) were retained in the logistic model, which could correctly predict lymph node status in 30 of 32 cases.

CONCLUSIONS

If our findings were confirmed, the identified gene pattern might be used to tailor the extent of lymph node dissection on a single patient basis.

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.

Effect of p27(KIP1) on cell cycle and apoptosis in gastric cancer cells

AIM

To elucidate the effect of p27(KIP1) on cell cycle and apoptosis regulation in gastric carcinoma cells.

METHODS

The whole length of p27(KIP1) cDNA was transfected into human gastric cancer cell line SCG7901 by lipofectamine. Expression of p27(KIP1) protein or mRNA was analyzed by Western blot and RNA dot blotting, respectively. Effect of p27(KIP1) on cell growth was observed by MTT assay and anchorage-independent growth in soft agar. Tumorigenicity in nude mice was used to assess the in vivo biological effect of p27(KIP1). Flow cytometry, TUNEL, and electron microscopy were used to assess the effect of p27(KIP1) on cell cycle and apoptosis.

RESULTS

Expression of p27(KIP1) protein or mRNA increased evidently in SCG7901 cells transfected with p27(KIP1). The cell growth was reduced by 31% at 48 h after induction with zinc determined by cell viability assay. The alteration of cell malignant phenotype was evidently indicated by the loss of anchorage-independent growth ability in soft agar. The tumorigenicity in nude mice was reduced evidently (0.55+/-0.14 cm vs 1.36+/-0.13 cm, P<0.01). p27(KIP1) overexpression caused cell arrest with 36% increase (from 33.7% to 69.3%, P<0.01) in G1 population. Prolonged p27(KIP1) expression induced apoptotic cell death reflected by pre-G1 peak in the histogram of FACS, which was also confirmed by TUNEL assay and electron microscopy.

CONCLUSION

p27(KIP1) can prolong cell cycle in G1 phase and lead to apoptosis. p27(KIP1) may be a good candidate for cancer gene therapy.

p27 downregulation and metallothionein overexpression in gastric cancer patients are associated with a poor survival rate

BACKGROUND AND OBJECTIVES

As a significant number of curatively treated gastric cancer patients will ultimately relapse, there is an urgent need to investigate new prognostic markers for identification of high-risk patients. In this study, we investigated the possible role of molecular markers involved in cell cycle regulation (B1 and D3 cyclins, and p27) and cell protection (metallothionein, MT) in predicting tumor behavior and clinical outcome in gastric cancer patients.

METHODS

Analysis of the above indicators was performed by immunohistochemistry on 73 gastric cancer patient samples and 25 normal gastric mucosa specimens.

RESULTS

Normal gastric mucosa cells displayed low expressions of B1 and D3 cyclins and MT, and intense p27 staining. Conversely, gastric tumor cells showed higher cyclin D3 and MT, and lower p27 expressions. B1 cyclin expressions were not different between normal and tumor tissue. p27 and MT expressions were altered in almost all cancer samples, and were strongly correlated with tumor progression. Advanced extent of the primary tumor, nodal metastasis, low p27, and high MT expressions were the best combination of variables for prediction of poor clinical outcome. Each marker predicted outcome better than staging based on tumor-node (TNM) system. Survival and recurrence rates decreased as molecular alterations increased. Finally, molecular profile determination correctly predicted the prognosis in patients with same TNM stage.

CONCLUSIONS

p27 and MT expressions strongly correlated with clinical outcome allowing to identify an unfavorable group of patients that may benefit from tailored treatments. The role of B1 and D3 cyclins in gastric cancer remains to be elucidated.

p27kip1 deficiency confers susceptibility to gastric carcinogenesis in Helicobacter pylori-infected mice

BACKGROUND & AIMS

Determining how Helicobacter pylori promotes gastric cancer and whether H pylori eradication decreases cancer risk would be helped by suitable murine models. Mice lacking the cyclin-dependent kinase inhibitor p27kip1 are susceptible to carcinogen-induced tumors. Furthermore, p27 stimulates gastric epithelial apoptosis and inhibits proliferation, expression is decreased by H pylori, and low levels are associated with a poor prognosis in gastric cancer. We therefore evaluated p27-deficient mice as a model for H pylori-associated gastric cancer.

METHODS

Wild-type and p27-/- C57BL/6 mice were infected with H pylori mouse-adapted Sydney strain at 6-8 weeks of age and 6-10 mice of each type were euthanized 15, 30, 45, 60, and 75 weeks later.

RESULTS

Uninfected p27-/- mice developed gastric hyperplasia. H pylori-infected p27-/- mice frequently developed intestinal metaplasia (40% at 30 weeks, 67% at 45 weeks), and after 60 weeks 7 of 12 mice developed significant dysplasia and gastric cancer, recapitulating human intestinal-type gastric carcinogenesis. Wild-type mice developed intestinal metaplasia only after 75 weeks of infection; significant gastric dysplasia was observed in 1 animal (P < .05 for each comparison with p27-/- mice). No disease developed in uninfected mice. H pylori infection in p27-/- mice was associated with significantly decreased apoptosis and increased epithelial proliferation, inflammation, and H pylori density compared with infection in wild-type mice.

CONCLUSIONS

p27 loss and H pylori colonization cooperate to produce gastric cancer. The p27-deficient mouse affords opportunities to examine the pathogenesis of H pylori in gastric carcinogenesis and to test eradication and chemopreventive strategies.

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.

Expression and hypermethylation of p27kip1 in hepatocarcinogenesis

AIM: To study the expressions of p27^kip1 protein and p27mRNA, the hypermethylation of p27^kip1 and the relation between them in various stages of hepatocarcinogenesis.

METHODS: p27 protein and p27mRNA were detected by immunohistochemical staining and in situ hybridization respectively in 68 cases of normal liver, liver cirrhosis, pericancerous cirrhosis and hepatocellular carcinoma (HCC). The hypermethylation of p27^kip1 was detected by methylation-specific PCR (MSP) in 44 cases of normal liver, liver cirrhosis, and HCC.

RESULTS: The positive rate of p27 protein was 66.7% (4/6) in normal liver, 60.0% (6/10) in liver cirrhosis, 50.0% (12/24) in pericancerous cirrhosis and 21.4% (6/28) in HCC. There were no statistical differences in normal liver, liver cirrhosis and pericancerous cirrhosis, but the positive rate of p27 protein significantly decreased in HCC compared to that in the other groups (P = 0.006, χ² = 7.664). The positive rate of p27^kip1 mRNA was 83.3% (5/6) in normal liver, 70.0% (7/10) in liver cirrhosis, 75.0% (18/24) in pericancerous cirrhosis and 25.0% (7/28) in HCC. There were no statistical differences in normal liver, liver cirrhosis and pericancerous cirrhosis, but the positive rate of p27^kip1 mRNA also significantly decreased in HCC compared to that in the other groups (P = 0.000, χ² = 16.600). In addition, there was a significant correlation between the expression of p27 protein and p27mRNA in the integrated group of normal liver and liver cirrhosis. However, no significant correlation was found between pericancerous cirrhosis and HCC. Using MSP, we found that 1 HCC in 44 cases (including 6 cases of normal liver, 10 cases of liver cirrhosis and 28 cases of HCC) was methylated, whose p27 protein and p27mRNA were negative.

CONCLUSION: The reduction or loss of p27 protein and p27mRNA are potentially involved in hepatocarcinogenesis. The hypermethylation of p27 might lead to the loss of p27mRNA transcription.

Cell proliferation, apoptosis and the related regulators p27, p53 expression in hepatocellular carcinoma

AIM: To investigate the expression of cell apoptosis, proliferation and the related regulators p27, p53 in hepatocellular carcinoma (HCC).

METHODS: The expression of p27, p53, proliferating cell nuclear antigen (PCNA) and apoptosis in 47 HCC specimens and 42 surrounding non-cancerous tissues were detected by the immunohistochemistry and terminal deoxy-nucleotidyl transferase-mediated nick end labeling (TUNEL) technique. Meanwhile, the clinical significance of them was analyzed combining with the clinicopathological factors and follow-up data.

RESULTS: (1) The average proliferating index and apoptotic index in HCC were significantly higher than that in adjacent liver tissues. The proliferating index was associated with extrahepatic metastasis. The apoptotic index was significantly lower in TNM stage I-II than in stage III-IV. The proliferating index of groups with p53-/p27+ was significantly lower than that in group with p53+/p27- (P = 0.030); (2) The level of p27 in the cytoplasmic fraction was higher in non-tumoral liver tissues and was associated with clinical stage; (3) Survival analysis showed advanced stage (P = 0.031) and with extrahepatic metastasis (P = 0.045) was significantly associated with shorter survival. In addition, the prognosis of patients with p53-/p27+ was longer than that of patients with p53+/p27- (P = 0.0356).

CONCLUSION: The p53 mutation and decreased p27 expression might be involved in the imbalance of proliferation and apoptosis in HCC. Cytoplasmic displacement might lead to the inactivation of p27 protein in HCC cells and acts early during carcinogenesis of HCC. The combined examination of p27, and p53 expression allows reliable estimation of prognosis for patients with primary hepatic carcinoma.

Genetic alterations in 102 primary gastric cancers by comparative genomic hybridization: gain of 20q and loss of 18q are associated with tumor progression

Gastric cancer is one of the most common cancers. Molecular events in the carcinogenesis of gastric cancer remain, however, largely undefined. We investigated changes in DNA copy number in 102 gastric cancers by CGH. We found changes in DNA copy number in all cases, with frequent (> or =30% of patients) gains at 20q, 8q, 20p, 7q, 17q, 5p, and 13q. Frequent (> or =20%) losses were found at 19p, 18q, 5q, 21q, 4p, 4q, 15q, and 17p. The mean number of total alterations was significantly lower in grade 3 and scirrhous-type carcinomas (10.81 in grade 3 vs 13.98 in grade 1 and grade 2, 9.31 in scirrhous-type vs 13.18 in medullary- and intermediate-type). The mean number of losses and total alterations were higher in tumors at pT2, pT3 and pT4 (4.68 and 12.77 in pT2, pT3, and pT4 vs 2.55 and 9.22 in pT1). The mean number of losses was higher in carcinomas with lymph node metastasis (4.83). The mean number of gains and total alterations were higher in carcinomas with venous invasion (8.44 and 13.28). Several chromosomal alterations were linked in a statistically significant manner to specific clinicopathological parameters. Gain of 17q, 20p, and 20q and loss of 4p were associated with the pattern of the cancer-stroma relationship; loss of 18q was associated with pT category; gain of 5p was associated with pN category; loss of 4q and loss of 21q were associated with lymphatic invasion; gain of 7p and loss of 4q and 18q were associated with venous invasion; and loss of 18q was associated with pathological stage. These data suggest that gain of 20q and loss of 18q might play an important role in the development and progression of gastric cancer. Moreover, some genes on 20q and 18q might be target genes of gastric cancer.

Expression of p27 in residual rectal cancer after preoperative chemoradiation predicts long-term outcome

BACKGROUND

Compared with surgery alone, preoperative radiotherapy and 5-fluorouracil-based chemotherapy (combined-modality therapy; CMT) improves outcomes in patients with locally advanced rectal cancer. Although numerous studies have focused on identifying molecular markers of prognosis in the primary rectal cancer before CMT, our aim was to identify markers of prognosis in residual rectal cancer after preoperative CMT.

METHODS

Sixty-seven patients with locally advanced (T3-4 and/or N1) rectal cancer were treated with preoperative radiotherapy (median, 5040 cGy) with or without 5-fluorouracil-based chemotherapy. Residual tumor in the resected specimen, available for 52 patients, was analyzed for tumor-node-metastasis stage, lymphovascular and/or perineural invasion, and immunohistochemical expression of p27, p21, p53, Ki-67, retinoblastoma gene, cyclin D1, and bcl-2. Recurrence-free survival (RFS) was determined by the Kaplan-Meier method and compared by the log-rank test.

RESULTS

With a median follow-up of 69 months, the overall 5-year RFS was 74%. RFS was significantly worse for patients with positive p27 expression (P = .005), T3-4 tumors (P = .02), and positive lymph nodes (P = .04) in the irradiated specimen. On multivariate analysis, positive p27 expression remained an independent negative prognostic factor for RFS (P = .04). None of the other proteins was significantly associated with RFS.

CONCLUSIONS

Our results indicate that positive p27 expression in rectal cancer after preoperative chemoradiation is an independent negative predictor of RFS. Expression of p27 in the residual rectal cancer may therefore identify patients with disease likely to be refractory to standard therapy and for whom investigational approaches should be strongly considered.

Expression and altered subcellular localization of the cyclin-dependent kinase inhibitor p27Kip1 in hepatocellular carcinoma

AIM: To investigate p27 expression in hepatocellular carcinoma (HCC), adjacent nontumoral and normal liver tissues, and to verify whether the subcellular localization of p27 was altered in HCC.

METHODS: The level of p27 in tumoral, nontumoral, and normal liver tissues were assessed by immunohistochemical (IHC) analysis. Parallel immunostaining was done for proliferating cell nuclear antigen (PCNA) to evaluate cell proliferation.

RESULTS: The labeling index (LI) of p27 in tumoral lesions was significantly lower than that in adjacent nontumoral lesions (t = 2.444, P = 0.017) and normal controls (t = 2.268, P = 0.029). The LI of p27 significantly decreased in patients with massive type (t = 2.227, P = 0.037) and infiltration (t = 2.197, P = 0.036). The prognosis of patients with higher p27 LI was longer than that of patients with lower p27 LI (P = 0.0247, log-rank test). The LI of PCNA was significantly higher in HCC than that in adjacent nontumoral lesions (t = 2.092, P = 0.041) and normal controls (t = 3.533, P = 0.002). There was no significant correlation between p27 expression and cell proliferation in tumor samples. The level of p27 in the cytoplasmic fraction was higher in tumoral and nontumoral liver tissues, and was associated with clinical stage (t = 2.520, P = 0.029) and the degree of invasion (t = 2.640, P = 0.019). Survival analysis showed that p27 was an independent prognosis marker for HCC patients.

CONCLUSION: These results suggest that p27 underexp-ressing in patients with HCC is closely associated with infiltration, metastasis, and prognosis. Alterations in the subcellular localization of p27 protein may occur early during hepatocarcinogenesis.

Expression of the Components of the Cip/Kip Family in Malignant Lymphoma of the Thyroid

OBJECTIVE

For evaluating the characteristics of human neoplasms, investigation of regulators of cell cycle progression is important. We studied three components of the Cip/Kip family, p57, p27 and p21, in malignant lymphomas of the thyroid.

METHODS

We immunohistochemically investigated the expression of the three proteins for 49 cases of thyroid lymphomas, as well as 10 cases of chronic thyroiditis.

RESULTS

In infiltrating lymphocytes in chronic thyroiditis, p57 and p27 were diffusely expressed, whereas p21 immunoreactivity was only occasionally observed. In lymphoma, decreased expression of p57 (less than 50% of lymphoma cells were positive) was observed in 24 cases (49.0%). p57 expression was inversely linked to the MIB-1 labeling index, grade of malignancy and aberrant p53 expression. Decreased expression of p27 was observed in 25 cases (51.0%), which was also related to the MIB-1 labeling index and aberrant p53 expression. On the other hand, p21 expression was occasional, and when the cut-off value was set at 3%, 38 cases (77.6%) were regarded as negative. P21 expression was not linked to any clinicopathological parameters.

CONCLUSION

These findings suggest that, among the 3 components of the Cip/Kip family, p57 and p27 play a role in negatively regulating the cell proliferation of thyroid lymphoma cells and decreased expression of them contributes to the progression of this disease.

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Molecule action mechanisms of NM-3 on human gastric cancer SGC-7901 cells in vivo or in vitro

AIM: To study the molecule action mechanisms of NM-3 on the growth of human gastric cancer SGC-7901 cells in vivo or in vitro.

METHODS: SGC-7901 from human non-differentiated gastric cancer cell line was cultured with NM-3 at 100 mg/mL for 24 h. We observed its inhibitory rate and the density of micro-vascular growth in grafted mice with human gastric cancer SGC-7901. The apoptosis of human gastric cancer SGC-7901 was revealed in NM-3 treatment group by using terminal deoxynucleotidyl transferase-mediated deoxy-uridine triphosphate-fluorescene nick end labeling (TUNEL) method and flow cytometry analysis.

RESULTS: The growth of SGC-7901 cells was markedly inhibited compared with control growp, which was smaller than that in normal saline control group (4.17 g ± 0.22 g vs 9.45 g ± 1.38 g, P < 0.01). The level of apoptosis of human gastric cell line SGC-7901 was obviously increased in NM-3 treatment group at 1 mg.L^-1 for 24 h. NM-3 inducing apoptotic index in NM-3 plus carboplatin group was 3.5 times that of carboplatin control group (TUNEL: 27.98% ± 6.12% vs 12.94% ± 2.12%, FACScan: 26.86% ± 5.69% vs 11.86% ± 1.09%, P < 0.01). Western blot analysis showed that the apoptotic index of human gastric cancer was elevated for 12, 24 and 36 h with an evident time-effect relationship in groups at 100 mg.L^-1. NM-3 enhanced the inhibitive effects and sensitivity of chemotherapy for human gastric cancer in nude mice. These results suggested that NM-3 played a key inhibitive role in the growth of grafted human gastric cancer in nude mice.

CONCLUSION: NM-3 can inhibit the growth of human gastric cancer cell line SGC-7901, and enhance the sensitivity of carboplatin on SGC-7901 and induced its apoptosis.